1,721,526 research outputs found
Codimension reduction in symmetric spaces
Get PDFIn this paper we give a short geometric proof of a generalization of a well-known result about reduction of codimension for submanifolds of Riemannian symmetric spacesFil: Di Scala, Antonio. Politecnico di Torino; ItaliaFil: Vittone, Francisco. Universidad Nacional de Rosario. Facultad de Cs.exactas Ingeniería y Agrimensura. Escuela de Cs.exactas y Naturales. Departamento de Matemática; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Mok's characteristic varieties and the normal holonomy group
Get PDFIn this paper we complete the study of the normal holonomy groups of complex submanifolds (non nec. complete) of Cn or CPn. We show that irreducible but non-transitive normal holonomies are exactly the Hermitian s-representations of [4, Table 1] (see Corollary 1.1). For each one of them we construct a non necessarily complete complex submanifold whose normal holonomy is the prescribed s-representation. We also show that if the submanifold has irreducible non-transitive normal holonomy then it is an open subset of the smooth part of one of the characteristic varieties studied by N. Mok in his work about rigidity of locally symmetric spaces. Finally, we prove that if the action of the normal holonomy group of a projective submanifold is reducible then the submanifold is an open subset of the smooth part of a so called join, i.e. the union of the lines joining two projective submanifolds.Fil: Di Scala, Antonio J.. Politecnico di Torino; ItaliaFil: Vittone, Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Exactas Ingeniería y Agrimensura. Escuela de Ciencias Exactas y Naturales. Departamento de Matemática; Argentin
La coccidiosi intestinale degli ovini e dei caprini: una parassitosi purtroppo sempre attuale.
No full textPhysiopathological mechanisms of abomasal Trichostrongylidae infections in small ruminants
No full textL’esame parassitologico diretto e la sua razionale applicazione nell’allevamento dei piccoli ruminanti.
No full text
Corchete y Curvatura
Get PDFThe first part of this article presents the definition of Lie Bracket related to commuting flows of vector fields. In the second part, basic definitions and of connections and curvature are given in order to emphasize the link bet- ween Lie Brackets and curvature. Finally, by using locally-defined connections, we give a short and original proof of a classical theorem of Beltrami. The article is addressed to a non specialist in local differential geometr
On an assertion in Riemann's Habilitationvortrag
Get PDFWe study an assertion in Riemann's Habilitation Lecture of 1854. Namely, the determination of the metric given sectional curvatures. We give several counterexamples to a Riemann's clai
Cystic echinococcosis in sheep: causes of the persistence in Sardinian.
No full textThe authors analyse the current epidemiological situation of sheep Cystic Echinococcosis
(CE) in Sardinia, where the prevalence of ovine CE is still very high (70%) and this
parassitosis is also frequently found in the human population. For this reason Sardinia
represents a peculiar model for CE study, because there are particular conditions that allow
Echinococcus granulosus to complete its life cycle. Some social and economical factors
support the persistence of sheep CE: over 3 million Sarda breed heads are extensively bred;
the presence, at farm level, of a strong relationship between dog, sheep and human; the low
commercial value of meat coming from adult sheep, whinch results in a large number of
sheep being slaughtered at home or on the farm rather than in authorized slaughterhouses.
Moreover Sardinia is the only Italian region where partially successful echinococcosis
control plans have been applied. The authors suggest some indirect and direct initiatives,
including the use of a new vaccine against the development of this metacestode in sheep, to
reduce the prevalence of CE
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