Academic literature on the topic 'MAT/03 Geometria'

TPS2622 Background: BMS-936558 is a fully human IgG4 monoclonal antibody targeted against human Programed Death-1 (PD1) receptor on activated T and B lymphocytes. Blocking of PD-1 prevents these activated cells from becoming anergic, thereby maintaining anti-tumor immunologic activity. Methods: The PK of BMS-936558 was characterized with data from a single ascending dose (SAD) and a multiple ascending dose (MAD) study in subjects with advanced solid malignancies. Subjects received a single IV infusion of 0.3 to 10 mg/kg BMS-936558 in the SAD study (MDX-1106-01 Study) and 0.1 to 10 mg/kg BMS-936558 every two weeks in the MAD study (MDX-1106-03/CA209003 Study). The PK of BMS-936558 was characterized by non-compartmental analysis of intensively sampled PK data from a SAD study, as well as by population PK analysis of available intensive and sparse PK data from the SAD and MAD studies, respectively. Results: The PK of BMS-936558 is linear in the studied dose range with dose-proportional increase in Cmax and AUC with low to moderate (20-44%) inter-subject variability. Geometric mean clearance ranged from 0.13 - 0.19 mL/h/kg, whereas mean volume of distribution ranged from 83 -113 mL/kg. The range of mean terminal elimination half-life of BMS-936558 is 17 to 25 days which is consistent with half-life of endogenous IgG4. BMS-936558 PK was adequately described by a linear two-compartment model, and there was no evidence of a contribution of target mediated drug disposition to drug elimination within tested dose range. Body weight and gender are potentially clinically significant covariate for both clearance and volume of distribution (> 20% effect); and baseline CRP, LDH, and albumin are potentially clinically significant covariates for CL. The body weight normalized dosing employed produces trough concentrations that are approximately constant over a wide range of body weights. Conclusions: The pharmacokinetics of BMS-936558 is dose-proportional and body weight normalized dosing is appropriate to ensure consistent exposure over a wide range of body weights.

We consider smooth complex projective varieties X which are rationally connected by rational curves of degree d with respect to a fixed ample line bundle L on X, and we focus our attention on conic connected manifolds (d=2) and on rationally cubic connected manifolds (d=3). Conic connected manifolds were studied by Ionescu and Russo; they considered conic connected manifolds embedded in projective space (i.e. L is very ample) and they proved a classification theorem for these manifolds. We show that their classification result holds true assuming just the ampleness of L. Moreover we give a different proof of a theorem due to Kachi and Sato; this result characterizes a special subclass of conic connected manifolds. As already said before, we study also rationally cubic connected manifolds. We prove that if rationally cubic connected manifolds are covered by “lines†, i.e. by curves of degree 1 with respect to L, then the Picard number of X is equal to or less than 3; moreover we show that if the Picard number is equal to 3 then there is a covering family of “lines†whose numerical class spans a negative extremal ray of the Kleiman-Mori cone of X. Unfortunately, for rationally cubic connected manifolds which don't admit a covering family of “lines†there isn't an upper bound on the Picard number. However we prove that if we consider rationally cubic connected manifolds which are not covered by “lines†but are Fano then up to a few exceptions in dimension 2 also the Picard number of these manifolds is equal to or less than 3. In particular, supposing that the dimension of X is greater than 2, we show that either the Picard number is equal to or less than 2 or X is the blow up of projective space along two disjoint subvarieties that are linear subspaces or quadrics.

In this thesis I've explored the theory of quaternionic slice regular functions. More precisely I've studied some rigidity properties, some differential issues and an application in complex differential geometry. This application concerns the constructions and classifications of orthogonal complex structures on open domains of the four dimensional euclidean space.

ABSTRACT: Roughly speaking, the moduli space of higher spin curves parametrizes equivalence classes of pairs (C, L) where C is a smooth genus g algebraic curve and L is a line bundle on it whose r-th tensor power is isomorphic to the canonical bundle of the curve. The aim of the talk is to discuss important geometrical properties of these spaces under different points of view: one possible compactification together with the description of the rational Picard group, their birational geometry in some low genus cases and their relation with some special locus inside the classical moduli spaces of curves.

Galois spaces, that is affine and projective spaces of dimension N ≥ 2 defined over a finite (Galois) field F_q, are well known to be rich of nice geometric, combinatorial and group theoretic properties that have also found wide and relevant applications in several branches of Combinatorics, as well as in more practical areas, notably Coding Theory and Cryptography. The systematic study of Galois spaces was initiated in the late 1950’s by the pioneering work of B. Segre [59]. The trilogy [34, 36, 42] covers the general theory of Galois spaces including the study of objects which are linked to linear codes. Typical such objects are plane arcs and their generalizations - especially caps and arcs in higher dimensions - whose code theoretic counterparts are distinguished types of error-correcting and covering linear codes. Their investigation has received a great stimulus from Coding Theory, especially in the last decades; see the survey papers [40, 41]. An important issue in this context is to ask for explicit constructions of small complete arcs and small complete caps. A cap in a Galois space is a set of points no three of which are collinear. A cap is complete if its secants (lines through two points of the set) cover the whole space. An arc in a Galois space of dimension N is a set of points no N+1 of which lying on the same hyperplane. In analogy with caps, an arc which is maximal with respect to set-theoretical inclusion is said to be complete. Also, arcs coincide with caps in Galois planes. From these geometrical objects, there arise linear codes which turn out to have very good covering properties, provided that the size of the set is small with respect to the dimension N and the order q of the ambient space. For the size t(AG(N,q)) of the smallest complete caps in a Galois affine space AG(N,q) of dimension N over F_q, the trivial lower bound is √2q^{N−1/2}. General constructions of complete caps whose size is close to this lower bound are only known for q even and N odd, see [16, 19, 29, 52]. When N is even, complete caps of size of the same order of magnitude as cq^{N/2}, with c a constant independent of q, are known to exist for both the odd and the even order case, see [16, 18, 28, 29, 31] (see also Section 2.2 and the references therein). Whereas, few constructions of small complete arcs in Galois spaces of dimension N>2 are known. In [65, 66, 67], small complete arcs having many points in common with the normal rational curve are investigated (see Section 4.2.3 for comparisons with our results). In this thesis, new infinite families of complete arcs and caps in higher dimensional spaces are constructed from algebraic curves defined over a finite field. In most cases, no smallest complete caps/arcs were previously known in the literature. Although caps and arcs are rather combinatorial objects, constructions and proofs sometimes heavily rely on concepts and results from Algebraic Geometry in positive characteristic.

Let C be a compact Riemann surface. Let us consider a finite group acting on CxC, having some elements that exchange the factors, and assume that the subgroup of those elements that do not exchange the factors acts freely. We call the quotient a Semi-isogenous Mixed Surface. In this work we investigate these surfaces and we explain how their geometry is encoded in the group. Based on this, we present an algorithm to classify the Semi-isogenous Mixed Surfaces with given geometric genus, irregularity and self-intersection of the canonical class. In particular we give the classification of Semi-isogenous Mixed Surfaces with K^2>0 and holomorphic Euler-Poincaré characteristic equal to 1, where new examples of minimal surfaces of general type appear. Minimality of Semi-isogenous Mixed Surfaces is discussed using two different approaches. The first one involves the study of the bicanonical system of such surfaces: we prove that we can relate the dimension of its first cohomology group to the rank of a linear map that involves only curves. The second approach exploits Hodge index theorem to bound the number of exceptional curves that live on a Semi-isogenous Mixed Surface.

This paper describes a novel approach to fabricating propeller blades to extremely high accuracy. The new approach includes iterative machining and rapid precision metrology. Iterative processes have been employed for decades in the optics industry. At Itek, robotics and computer-controlled surfacing techniques are used for iterative machining operations to produce ultra-precision optical surfaces. The technology developed at Itek for large optics has strong potential to transfer to the propeller industry. The surface of a propeller is difficult to measure accurately because of its odd shape and rapidly changing geometry, however, the Litton/Itek Surfitek Profilometer is capable of making this measurement to high accuracy. Surfitek was used to measure an Aegis Class Destroyer propeller blade to better than 0.001" over the entire surface. Data was obtained at an average rate of one point per second, manually, while rates of up to ten measurements per second are achievable under machine control. The system is capable of operating in contacting or non-contacting modes and includes software to calculate departures of the measured surface from the desired nominal, develop an error map of the measured surface and provide machine command control for an iterative manufacturing surfacing operation. The measurement equipment and data reduction techniques used in a propeller manufacturing demonstration, as well as the initial results obtained using iterative machining techniques arc discussed.