Thresholds for hanger slackening and cable shortening in the Melan equation for suspension bridges

The Melan equation for suspension bridges is derived by assuming small displacements of the deck and inextensible hangers. We determine the thresholds for the validity of the Melan equation when the hangers slacken, thereby violating the inextensibility assumption. To this end, we preliminarily study the possible shortening of the cables: it turns out that there is a striking difference between even and odd vibrating modes since the former never shorten the cables. These problems are studied both on beams and plates

Role of the transcription factor Erg in inflammation

Pro-inflammatory and atherogenic stimuli up-regulate the expression of endothelial adhesion molecules which support the extravasation of leukocytes into the sub-endothelial space. This process drives plaque progression and contributes to its complications. Erg is an ETS transcription factor constitutively expressed in EC which regulates angiogenesis and endothelial homeostasis. Recently, Erg was shown to inhibit endothelial expression of the chemokine IL-8. In EC, Erg expression is down-regulated by the pro-inflammatory cytokine TNF-alpha, through a mechanism which appears to involve Erg protein degradation. These data suggest that Erg may be involved in inflammation. To test this hypothesis, I modulated Erg expression in HUVEC by inhibition with antisense or over-expression using adenovirus encoding for Erg (AdErg). Basal ICAM-1 expression was up-regulated following Erg inhibition, and down-regulated by Erg over-expression. Both of these effects were transcriptional, as shown by a luciferase reporter assay. Over-expression of Erg could inhibit TNF-dependent up-regulation of ICAM-1 and ICAM-1 promoter activity. Thus Erg acts as a transcriptional repressor of ICAM-1 expression in resting and activated EC. This pathway involves NF-kB, since both basal and TNF-α-induced NF-kB activity was repressed by AdErg, and Erg over-expression inhibited the TNF-α induction of NF-kB p65 phosphorylation. In vitro, Erg over-expression led to decreased adhesion of leukocytes to TNF-stimulated HUVEC. In vivo, local injection of AdErg in the mouse paw resulted in reduction of TNF-α-induced inflammation. Interestingly, staining of human coronary artery plaques showed that Erg is absent from activated endothelium over the vulnerable region of the plaque. In conclusion, I propose that Erg exerts a protective role in the endothelium by repressing pro- inflammatory signaling and gene expression. These results suggest a novel approach to anti-inflammatory therapies

New record of the great white shark Carcharodon carcharias from Lampedusa

This new record confirms that the Central Mediter ranean, and Sicilian coasts in particular, still represent a key area for the population of Mediterranean white sharks, but also for other shark species (Bilecenoglu et al., 2013); in fact, 43% of all white shark sightings in the Italian seas (Micarelli et al., 2011) are from this area

Pojava parazita Otodistomum veliporum u štrcalu morskog psa drkovne (Dalatias licha)

The presence of the digenean Otodistomum veliporum is reported here for the first time as a parasite in the spiracle of a Mediterranean specimen of the kitefin shark Dalatias licha.Prvi put je zabilježena u znanstvenoj literaturi prisutnost parazita Otodistomum veliporum u štrcalu morskog psa drkovne Dalatias licha

Observations about surface behaviour of the great white shark Carcharodon carcharias (L.) in presence of passive preys at Dyer Island (Southafrica)

During 4 study expeditions in SouthAfrica, performed in 2000, 2003, 2004 and 2005, observations about surface predatory behaviour of the Great White Shark in presence of passive preys were made. Observations were carried out by Unlimited Shark Diving boats and by cage diving around Dyer Island, about 5 miles far from Gansbaai. During the 27 observation days were identified 78 different specimens, that exhibited 8 different behaviours. The Great White Shark population observed around Dyer island shows a greater variety of behaviours than the population studied along the California coasts

Solenoidal extensions in domains with obstacles: explicit bounds and applications to Navier-Stokes equations

We introduce a new method for constructing solenoidal extensions of fairly general boundary data in (2d or 3d) cubes that contain an obstacle. This method allows us to provide explicit bounds for the Dirichlet norm of the extensions. It runs as follows: by inverting the trace operator, we first determine suitable extensions, not necessarily solenoidal, of the data; then we analyze the Bogovskii problem with the resulting divergence to obtain a solenoidal extension; finally, by solving a variational problem involving the infinity-Laplacian and using ad hoc cutoff functions, we find explicit bounds in terms of the geometric parameters of the obstacle. The natural applications of our results lie in the analysis of inflow-outflow problems, in which an explicit bound on the inflow velocity is needed to estimate the threshold for uniqueness in the stationary Navier-Stokes equations and, in case of symmetry, the stability of the obstacle immersed in the fluid flow

Discrepancy between tumor response and hematologic response in a patient with thymoma and aplastic anemia treated with ciclosporin

Pure red cell aplasia (PRCA) represents one of the most common paraneoplastic syndromes in patients with advanced thymoma. Ciclosporin is a very effective treatment in this condition, and it seems to have also a direct anti-cancer effect. We provide a case of radiological response of thymoma associated with the total absence of response of PRCA in a patient treated with ciclosporin. A 60-year-old man with advanced thymoma underwent first-line chemotherapy, achieving a partial disease response followed by 2 years of stable disease. After disease progression, the patient developed a PRCA, later expanded to platelets, and then he started therapy with ciclosporin, without any blood improvement. The CT revaluation after three months of ciclosporin therapy showed tumor shrinkage, although the inefficacy in the treatment of PRCA. The paper reports a case of dissociation between oncological and hematological response in a patient with thymoma-related PRCA, suggesting that the pathology of this condition deserves novel investigations. Further studies should be conducted to acquire more exhaustive knowledge and permit the integrated treatment of oncological and hematological conditions