Giorgio Ottaviani

Let ${\cal M}_{I\!\! P^3}(c_1,c_2)$ be the moduli space of stable rank-$2$ vector bundles on $I\!\! P^3$ with Chern classes $c_1$, $ c_2$. We prove the following results. 1) Let $0 \le \beta < \gamma $ be two integers, ($\gamma \ge 2)$, such that $2\gamma-3\beta>0$; then ${\cal M}_{I\!\! P^3}(0,2\gamma^2-3\beta^2)$ is singular (the case $\beta =0$ was previously proved by M. Maggesi). 2) Let $0 \le \beta < \gamma $ be two odd integers ($\gamma \ge 5)$, such that $2\gamma-3\beta+1>0$; then ${\cal M}_{I\!\! P^3}(-1,2(\gamma/2)^2-3(\beta/2)^2+1/4)$ is singular. In particular ${\cal M}_{I\!\! P^3}(0,5)$, ${\cal M}_{I\!\! P^3}(-1,6)$ are singular.

A critical involvement of the endocannabinoid/cannabinoid receptor system in diabetes and its complications has been recognized. Experimental evidence suggested that activation of the cannabinoid receptor type 2 (CB2), which is expressed in the kidney by podocytes and inflammatory cells, had a protective role in early streptozotocin-induced type 1 diabetes in mice. No experimental evidence is so far available on the effects of CB2 agonists in type 2 diabetes. In this study, we investigated the effects of a CB2 agonist given at a phase of overt disease on renal functional and structural changes in BTBR ob/ob mice, a model of type 2 diabetic nephropathy. BTBR ob/ob mice received, from 10 to 21 weeks of age, vehicle, the selective CB2 agonist HU910, or lisinopril used as standard therapy for comparison. BTBR wild-type mice served as controls. Treatment with CB2 agonist reduced progressive albuminuria of BTBR ob/ob mice to a similar extent as ACE inhibitor. The antiproteinuric effect of CB2 agonist was associated with the amelioration of the defective nephrin expression in podocytes of diabetic mice. CB2 agonist limited mesangial matrix expansion, fibronectin accumulation and sclerosis. Glomerular infiltration of Mac-2-positive monocytes/machrophages was attenuated by CB2 agonist, at least in part due to the drug&amp;amp;amp;amp;amp;#39;s ability to reduce MCP-1 chemotactic signals. Renoprotective effects of CB2 were similar to those achieved by ACE inhibitor. These results suggest that CB2 agonism is a potential option to be added to the available therapeutic armamentarium for type 2 diabetic nephropathy.

We study some properties of the natural action of $SL(V_0) \times...\times SL(V_p)$ on nondegenerate multidimensional complex matrices $A\in\P (V_0\otimes...\otimes V_p)$ of boundary format(in the sense of Gelfand, Kapranov and Zelevinsky); in particular we characterize the non stable ones,as the matrices which are in the orbit of a &quot;triangular&quot; matrix, and the matrices with a stabilizer containing $\C^*$, as those which

A high-performance liquid chromatographic method with ultraviolet photometric detection has been developed for the quantitation of cotinine and trans-3&#39;-hydroxycotinine in human serum. A solid-phase extraction procedure was performed for the analytes and the internal standard, N-ethylnorcotinine, before chromatography. The use of a 30-cm reversed-phase column and a mobile phase of water-methanol-0.1 M sodium acetate-acetonitrile (67:24.5:6.5:2, v/v), pH 4.3, prevented the co-elution of caffeine with cotinine. The limit of quantitation observed with this method was 5 ng/ml for both cotinine and trans-3&#39;-hydroxycotinine. The present method proved useful for the determination of serum levels of these metabolites, correlating with nicotine daily intake.

Programmazione lineare: Forma standard dei problemi di P.L. Metodo del Simplesso. Esame dei tre casi della tabella del simplesso. Trasformazione pivotale. Costruzione delle tabelle successive. Criterio di uscita. Criterio di entrata. Metodo della ricerca della base in due fasi. Geometria della Programmazione Lineare. Vertici della regione ammissibile. Caratterizzazione dei vertici. Esistenza dei vertici ammissibili e ottimali. Forma canonica di un problema di massimo e minimo. Definizione di coppia di problemi duali. Teorema fondamentale della dualità o dell&#x27;alternativa. Programma ottimale duale e relativi teoremi. Soluzione del problema duale. Interpretazione della dualità. Il problema del trasporto: presentazione del modello matematico e algoritmo risolutivo. Programmazione lineare intera: Formulazione di un problema di P.L.I. Relazioni tra P.L. e P.L.I. Inviluppo convesso. Disuguaglianze valide. Metodo dei piani di taglio. Metodo del Branch and Bound. Criteri di potatura. Re...

This work was devoted to the search for new artificial membranes allowing a rapid evaluation of passive human skin permeation of compounds with a parallel artificial membrane permeability assay (PAMPA). Effective permeability coefficients (Pe) determined for a set of compounds using the PAMPA technique with isopropyl myristate (IPM) and silicone oil, alone or in mixture, were compared to the corresponding human skin permeability coefficient values (Kp). A good correlation between Pe and Kp was found for compounds tested through a membrane consisting of 70% silicone and 30% IPM. Moreover, positive correlation between the membrane retention of compounds and stratum corneum/water partition coefficients (PSC) was established. These results showed that this new artificial membrane, defined as PAMPA-skin, is able to mimic the main barrier properties of human stratum corneum and can be used for the fast prediction of passive human skin permeability coefficients.

We define new classes of modules of equations for secant varieties of Veronese varieties using representation theory and geometry. We also revisit some old modules of equations (catalecticant minors) to determine when they are sufficient to give scheme-theoretic defining equations.

Polycide gate structures are widely used in ULSI (Ultra Large Scale Integration) devices. The distribution of the dopant between the various layers is of major concern. The effects of the fluorine incorporated during WSi2 deposition have been discussed because fluorine may diffuse into the gate oxide. We have studied the redistribution of boron, phosphorus and fluorine in WSi2/poly/SiO2/poly/SiO2/Si (bulk) gate