Search results for "Varietie"
showing 10 items of 72 documents
On Almost Nilpotent Varieties of Linear Algebras
2020
A variety \(\mathcal {V}\) is almost nilpotent if it is not nilpotent but all proper subvarieties are nilpotent. Here we present the results obtained in recent years about almost nilpotent varieties and their classification.
Yield And Competitive Ability Against Weeds Of Mixtures Between Old And Modern Wheat Varieties
2018
Durum wheat is the keystone of the agro-ecosystems in the arable land of the Mediterranean environments and an important part of its area falls within organic farms. For this crop competition exerted by weeds for the use of resources (natural and auxiliary) can determine drastic yield and quality reductions (Ruisi et al., 2015). In organic farming such critical issue is often addressed through a remodelling of several techniques such as soil tillage management, sowing time, plant density and genotype choice. With regard to the latter, there is a growing interest by organic farmers towards the old varieties as they, compared to the modern varieties, have a definitely greater competitive weed…
On base loci of higher fundamental forms of toric varieties
2019
We study the base locus of the higher fundamental forms of a projective toric variety $X$ at a general point. More precisely we consider the closure $X$ of the image of a map $({\mathbb C}^*)^k\to {\mathbb P}^n$, sending $t$ to the vector of Laurent monomials with exponents $p_0,\dots,p_n\in {\mathbb Z}^k$. We prove that the $m$-th fundamental form of such an $X$ at a general point has non empty base locus if and only if the points $p_i$ lie on a suitable degree-$m$ affine hypersurface. We then restrict to the case in which the points $p_i$ are all the lattice points of a lattice polytope and we give some applications of the above result. In particular we provide a classification for the se…
Electrochemical tomato (Solanum lycopersicum L.) characterisation using contact probe in situ voltammetr
2015
[EN] An in situ electrochemical contact probe methodology for characterising tomato samples is proposed. It is based on the record of the voltammetric response of antioxidant compounds when glassy carbon electrodes are inserted into the pericarp of fresh tomato specimens cut in half. The absence of pretreatment and in situ sampling avoid sample contamination and the oxidation of air-sensitive compounds thus increasing the representativity of the analytical data relative to conventional electrochemical analysis. Characteristic voltammetric responses recorded for such compounds, including rutin, chlorogenic acid, naringenin, naringenin chalcone and ascorbic acid have been obtained. A positive…
Conceptualizing and Measuring the Quality of Democracy: The Citizens' Perspective
2018
In recent years, several measurements of the quality of democracy have been developed (e.g. Democracy Barometer, Varieties of Democracy Project). These objective measurements focus on institutional and procedural characteristics of democracy. This article starts from the premise that in order to fully understand the quality of democracy such objective measurements have to be complemented by subjective measurements based on the perspective of citizens. The aim of the article is to conceptualize and measure the subjective quality of democracy. First, a conceptualization of the subjective quality of democracy is developed consisting of citizens’ support for three normative models of democracy …
Homological Projective Duality for Determinantal Varieties
2016
In this paper we prove Homological Projective Duality for crepant categorical resolutions of several classes of linear determinantal varieties. By this we mean varieties that are cut out by the minors of a given rank of a n x m matrix of linear forms on a given projective space. As applications, we obtain pairs of derived-equivalent Calabi-Yau manifolds, and address a question by A. Bondal asking whether the derived category of any smooth projective variety can be fully faithfully embedded in the derived category of a smooth Fano variety. Moreover we discuss the relation between rationality and categorical representability in codimension two for determinantal varieties.
Deformations of Calabi-Yau manifolds in Fano toric varieties
2020
In this article, we investigate deformations of a Calabi-Yau manifold $Z$ in a toric variety $F$, possibly not smooth. In particular, we prove that the forgetful morphism from the Hilbert functor $H^F_Z$ of infinitesimal deformations of $Z$ in $F$ to the functor of infinitesimal deformations of $Z$ is smooth. This implies the smoothness of $H^F_Z $ at the corresponding point in the Hilbert scheme. Moreover, we give some examples and include some computations on the Hodge numbers of Calabi-Yau manifolds in Fano toric varieties.
Hurwitz spaces of triple coverings of elliptic curves and moduli spaces of abelian threefolds
2002
We prove that the moduli spaces A_3(D) of polarized abelian threefolds with polarizations of types D=(1,1,2), (1,2,2), (1,1,3) or (1,3,3) are unirational. The result is based on the study of families of simple coverings of elliptic curves of degree 2 or 3 and on the study of the corresponding period mappings associated with holomorphic differentials with trace 0. In particular we prove the unirationality of the Hurwitz space H_{3,A}(Y) which parameterizes simply branched triple coverings of an elliptic curve Y with determinants of the Tschirnhausen modules isomorphic to A^{-1}.
Corpus Analysis and Register Variation: a field in need of an update
2013
Abstract This study reviews the development of research on register variation (RV) over the last century to the present, emphasizing the influence of corpus analyses on its greatest advances and also on its major weaknesses and ambiguities. In search of practical and useful methods to analyse language registers, in the second part of the paper, the authors sketch a different approach to RV which has been used over the last ten years in language teaching at university level and professional communication training.
Important varieties of Sicily
2012
Sicily is an island to the south and west of Italy that is close to the “toe of the boot”, in the Mediterranean Sea. Its physical characteristics are representative of the Mediterranean region with its mountainous terrain and volcanoes, rugged coast, numerous beaches and blue water, scenic villages, and a diverse agriculture including wine grapes, citrus, olives, herbs, grains and seasonal vegetables. The climate is warm to hot, and the growing season is long. Located at the 36-38 degree latitude, Sicily is only about 160 kilometers (100 miles) from the north coast of Africa near Tunisia. It is also the midpoint east and west in the Mediterranean Sea. Through history the region was controll…