Harnack inequality and regularity for degenerate quasilinear elliptic equations

We prove Harnack inequality and local regularity results for weak solutions of a quasilinear degenerate equation in divergence form under natural growth conditions. The degeneracy is given by a suitable power of a strong $A_\infty$ weight. Regularity results are achieved under minimal assumptions on the coefficients and, as an application, we prove $C^{1,\alpha}$ local estimates for solutions of a degenerate equation in non divergence form

Edge channel mixing induced by potential steps in an integer quantum Hall system

We investigate the coherent mixing of co-propagating edge channels in a quantum Hall bar produced by step potentials. In the case of two edge channels it is found that, although a single step induces only a few percent mixing, a series of steps could yield 50% mixing. In addition, a strong mixing is found when the potential height of a single step allows a different number of edge channels on the two sides of the step. Charge density probability has been also calculated even for the case where the step is smoothened.Comment: final version: 7 pages, 6 figure

Preliminary realization of an electric-powered hydraulic pump system for a waste compactor truck and a techno-economic analysis

Most industrial trucks are equipped with hydraulic systems designed for specic operations, for which the required power is supplied by the internal combustion engine (ICE). The largest share of the power consumption is required by the hydraulic system during idling operations, and, consequently, the current literature focuses on energy saving strategies for the hydraulic system rather than making the vehicle traction more efficient. This study presents the preliminary realization of an electric-powered hydraulic pump system (e-HPS) that drives the lifting of the dumpster and the garbage compaction in a waste compactor truck, rather than traditional ICE-driven hydraulic pump systems (ICE-HPSs). The different components of the e-HPS are described and the battery pack was modelled using the kinetic battery model. The end-of-life of the battery pack was determined to assess the economic feasibility of the proposed e-HPS for the truck lifespan, using numerical simulations. The aim was twofold: To provide an implementation method to retrofit the e-HPS to a conventional waste compactor truck and to assess its economic feasibility, investigating fuel savings during the use phase and the consequent reduction of CO2 emissions. Results show that the total lifespan cost saving achieved a value of 65,000. Furthermore, total CO2 emissions for the e-HPS were about 80% lower than those of the ICE-HPS, highlighting that the e-HPS can provide significant environmental benefits in an urban context

La regolazione dei tirocini formativi in Italia dopo la legge Fornero. L’attuazione a livello regionale delle Linee-guida 24 gennaio 2013: mappatura e primo bilancio

Del tema degli stage – e dei tanti abusi in materia – continuano a occuparsi i vecchi e i nuovi media e, con sempre maggiore intensità e preoccupazione, anche gli addetti ai lavori. Manca ancora, tuttavia, un puntuale lavoro di monitoraggio e di bilancio volto, per un verso, a ricostruire anche solo in termini descrittivi il complesso quadro regionale di riferimento e a valutare in termini critici e ricostruttivi, per l’altro verso, se sia stato effettivamente raggiunto l’obiettivo della legge Fornero, quello di definire un quadro normativo omogeneo su scala nazionale ancorché la materia dei tirocini sia di esclusiva competenza regionale. In mancanza di un quadro di riferimento istituzionale si è ritenuto utile colmare questo vuoto con un volume ADAPT University Press. Si tratta di un lavoro minuzioso, innanzitutto di monitoraggio delle normative regionali. Un apposito database dedicato al tema dei tirocini del nuovo sito di ADAPT, www.transizionioccupazionali.it, contiene la proiezione informatica di questo volume con tutte le normative di riferimento, che verranno aggiornate

Hierarchical Model for the Evolution of Cloud Complexes

The structure of cloud complexes appears to be well described by a "tree structure" representation when the image is partitioned into "clouds". In this representation, the parent-child relationships are assigned according to containment. Based on this picture, a hierarchical model for the evolution of Cloud Complexes, including star formation, is constructed, that follows the mass evolution of each sub-structure by computing its mass exchange (evaporation or condensation) with its parent and children, which depends on the radiation density at the interphase. For the set of parameters used as a reference model, the system produces IMFs with a maximum at too high mass (~2 M_sun) and the characteristic times for evolution seem too long. We show that these properties can be improved by adjusting model parameters. However, the emphasis here is to illustrate some general properties of this nonlinear model for the star formation process. Notwithstanding the simplifications involved, the model reveals an essential feature that will likely remain if additional physical processes are included. That is: the detailed behavior of the system is very sensitive to variations on the initial and external conditions, suggesting that a "universal" IMF is very unlikely. When an ensemble of IMFs corresponding to a variety of initial or external conditions is examined, the slope of the IMF at high masses shows variations comparable to the range derived from observational data. (Abridged)Comment: Latex, 29 pages, 13 figures, accepted for publication in Ap

Screening and Management of Coronary Artery Disease in Kidney Transplant Candidates

Cardiovascular disease (CVD) is a major cause of morbidity and mortality in patients with chronic kidney disease (CKD), especially in end-stage renal disease (ESRD) patients and during the first year after transplantation. For these reasons, and due to the shortage of organs available for transplant, it is of utmost importance to identify patients with a good life expectancy after transplant and minimize the transplant peri-operative risk. Various conditions, such as severe pulmonary diseases, recent myocardial infarction or stroke, and severe aorto-iliac atherosclerosis, need to be ruled out before adding a patient to the transplant waiting list. The effectiveness of systematic coronary artery disease (CAD) treatment before kidney transplant is still debated, and there is no universal screening protocol, not to mention that a nontailored screening could lead to unnecessary invasive procedures and delay or exclude some patients from transplantation. Despite the different clinical guidelines on CAD screening in kidney transplant candidates that exist, up to today, there is no worldwide universal protocol. This review summarizes the key points of cardiovascular risk assessment in renal transplant candidates and faces the role of noninvasive cardiovascular imaging tools and the impact of coronary revascularization versus best medical therapy before kidney transplant on a patient’s cardiovascular outcome

Late onset of hypoxemia due to a pulmonary arteriovenous malformation during selective estrogen receptor modulator therapy.

A76-year-old woman with unexplained hypoxemia and severe exertional dyspnea was admitted to our department. The symptoms had appeared during tamoxifen therapy after resection of breast carcinoma; history revealed recurrent upper gastrointestinal bleeding, epistaxis, and a granddaughter deceased because of a cerebral arteriovenous malformation. Chest computed tomography scan showed the presence of a highly vascularized nodule in the right lower lobe. Right pulmonary artery angiography demonstrated a large pulmonary arteriovenous malformation (PAVM) (Online Video 1) with massive right-to-left shunt (A, B, C; Online Video 2); this confirmed the diagnosis of hereditary hemorrhagic telangiectasia (1). The arrows point to the right upper pulmonary vein. We decided to percutaneously close the PAVM. An occlusion test was performed before the procedure (D); O2 saturation rose from 87% to 96%. The PAVM was subsequently closed using a vascular occlusion device (E) with complete abolishment of the right-to-left shunt (F; Online Video 3). It is likely that selective estrogen receptor modulator therapy may have been responsible for the enlargement of the PAVM in our patient (2)

Levels of serum osteocalcin and some electrolytes in foal during the first six months of life (Brief Report)

Abstract. Bone is a dynamic tissue characterized by continuous bone formation and bone resorption. The transformation of the primordial part of the long bones (the cartilaginous matrix during the embryonal period) into the definitive bone (lamellar bone tissue) is completed after puberty. Osteocalcin, also called the vitamin k-dependent protein of bone and synthesized predominantly by osteoblasts and in lower way by odontoblasts, is incorporated into the extracellular matrix of bone (LEPAGE et al. 2001) and it may function as a useful indicator of the equine bone growth rate which decreases considerably with age. In particular, osteocalcin or bone Gla-protein is a small abundant non-collagenous calcium binding protein, indigenous to the organic matrix of bone dentin and possibly other mineralized tissue, which circulates in the blood (LEPAGE et al. 1991). It is accepted as a marker of osteoblast activity (RISTELI and RISTELI 1993) and plays a not yet defined role in the regulation of bone turnover (BOSKEY et al. 1998)