A Kato's second type representation theorem for solvable sesquilinear forms

Kato's second representation theorem is generalized to solvable sesquilinear forms. These forms need not be non-negative nor symmetric. The representation considered holds for a subclass of solvable forms (called hyper-solvable), precisely for those whose domain is exactly the domain of the square root of the modulus of the associated operator. This condition always holds for closed semibounded forms, and it is also considered by several authors for symmetric sign-indefinite forms. As a consequence, a one-to-one correspondence between hyper-solvable forms and operators, which generalizes those already known, is established.Comment: 20 page

A Survey on Solvable Sesquilinear Forms

The aim of this paper is to present a unified theory of many Kato type representation theorems in terms of solvable forms on Hilbert spaces. In particular, for some sesquilinear forms $\Omega$ on a dense domain $\mathcal{D}$ one looks for an expression $$\Omega(\xi,\eta)=\langle T\xi , \eta\rangle, \qquad \forall \xi\in D(T),\eta \in \mathcal{D},$$ where $T$ is a densely defined closed operator with domain $D(T)\subseteq \mathcal{D}$. There are two characteristic aspects of solvable forms. Namely, one is that the domain of the form can be turned into a reflexive Banach space need not be a Hilbert space. The second one is the existence of a perturbation with a bounded form which is not necessarily a multiple of the inner product.Comment: 11 page

Finitely generated abelian groups of units

In 1960 Fuchs posed the problem of characterizing the groups which are the groups of units of commutative rings. In the following years, some partial answers have been given to this question in particular cases. In this paper we address Fuchs' question for {\it finitely generated abelian} groups and we consider the problem of characterizing those groups which arise in some fixed classes of rings $\mathcal C$, namely the integral domains, the torsion free rings and the reduced rings. To determine the realizable groups we have to establish what finite abelian groups $T$ (up to isomorphism) occur as torsion subgroup of $A^*$ when $A$ varies in $\mathcal C$, and on the other hand, we have to determine what are the possible values of the rank of $A^*$ when $(A^*)_{tors}\cong T$. Most of the paper is devoted to the study of the class of torsion-free rings, which needs a substantially deeper study.Comment: 28 page

The Relationship Between Stellar Light Distributions of Galaxies and their Formation Histories

A major problem in extragalactic astronomy is the inability to distinguish in a robust, physical, and model independent way how galaxy populations are related to each other and to their formation histories. A similar, but distinct, and also long standing question is whether the structural appearances of galaxies, as seen through their stellar light distributions, contain enough physical information to offer this classification. We argue through the use of 240 images of nearby galaxies that three model independent parameters measured on a single galaxy image reveal its major ongoing and past formation modes, and can be used as a robust classification system. These parameters quantitatively measure: the concentration (C), asymmetry (A) and clumpiness (S) of a galaxy's stellar light distribution. When combined into a three dimensional `CAS' volume all major classes of galaxies in various phases of evolution are cleanly distinguished. We argue that these three parameters correlate with important modes of galaxy evolution: star formation and major merging activity. This is argued through the strong correlation of Halpha equivalent width and broad band colors with the clumpiness parameter, the uniquely large asymmetries of 66 galaxies undergoing mergers, and the correlation of bulge to total light ratios, and stellar masses, with the concentration index. As an obvious goal is to use this system at high redshifts to trace evolution, we demonstrate that these parameters can be measured, within a reasonable and quantifiable uncertainty, with available data out to z ~ 3 using the Hubble Space Telescope GOODS ACS and Hubble Deep Field images.Comment: ApJS, in press, 30 pages, Figures 15 and 16 are in color. For a full resolution version, please go to http://www.astro.caltech.edu/~cc/cas.p

Cuidados de enfermería sobre acceso venoso periférico

Desde el momento de la internación de un paciente pediátrico y hasta el momento del alta médica, el personal de enfermería está encargado de brindar cuidados y satisfacer la necesidad del dicho paciente. Una de esas necesidades que debe brindar es la integridad cutánea. El acceso venoso periférico es un procedimiento invasivo consistente en la colocación de un catéter en una vena periférica para realizar tratamientos intravenosos de corta duración, administración de medicamentos o sustancias con fines diagnóstico. Al momento de la colocación de estas vías, el personal de enfermería requiere un amplio conocimiento del procedimiento, del equipo necesario y de las técnicas de asepsia en el cuidado, así mismo no debe olvidar la parte anímica del paciente. Pero los cuidados de enfermería al paciente con una vía periférica no solo se limitan a la propia acción de colocar el catéter o seleccionar la vía, sino también es importante dar continuidad a los mismos durante el tiempo que permanezca colocado el catéter, de manera que por medio de la valoración, registro, cambio de apósito, cambio de catéter y limpieza, se brinde seguridad, comodidad y se puedan detectar precozmente posibles complicaciones. El presente trabajo de investigación tiene por objetivo general determinar cuál es el conocimiento y cuidados de enfermería sobre acceso venoso periférico, en el servicio de internación III, del Hospital Dr. Humberto Notti, Mendoza, octubre 2013.Fil: Corso, Silvia. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Escuela de Enfermería..Fil: Flores, Fernando. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Escuela de Enfermería.