1,467 research outputs found
Intrinsic Spectral Geometry of the Kerr-Newman Event Horizon
We uniquely and explicitly reconstruct the instantaneous intrinsic metric of
the Kerr-Newman Event Horizon from the spectrum of its Laplacian. In the
process we find that the angular momentum parameter, radius, area; and in the
uncharged case, mass, can be written in terms of these eigenvalues. In the
uncharged case this immediately leads to the unique and explicit determination
of the Kerr metric in terms of the spectrum of the event horizon. Robinson's
``no hair" theorem now yields the corollary: One can ``hear the shape" of
noncharged stationary axially symmetric black hole space-times by listening to
the vibrational frequencies of its event horizon only.Comment: Final version with improved abstract, updated references, corrected
typos, and additional discussio
Activated carbons as catalytic support for Cu nanoparticles
There are a wide range of catalytic applications for Cu-based nanoparticles materials, since Cu is an
abundant and inexpensive metal and Cu nanoparticles possess unusual electrical, thermal and
optical properties. The possible modification of the chemical and physical properties of these
nanoparticles using different synthetic strategies and conditions and/or via postsynthetic chemical
treatments has been largely responsible for the rapid growth of interest in these nanomaterials and
their applications in catalysis. A previous work have explored the possibilities of SBA-15 (1,2) as
support for Cu nanoparticles. In the present contribution, those results will be compared with the
use of a carbon material as support, since activated carbon present many advantages with respect
SBA, as the high surface area.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Master Majorana neutrino mass parametrization
After introducing a master formula for the Majorana neutrino mass matrix we
present a master parametrization for the Yukawa matrices automatically in
agreement with neutrino oscillation data. This parametrization can be used for
any model that induces Majorana neutrino masses. The application of the master
parametrization is also illustrated in an example model, with special focus on
its lepton flavor violating phenomenology.Comment: 5 pages, 3 figures and 2 tables; v2: minor corrections, matches
published versio
General parametrization of Majorana neutrino mass models
We discuss a general formula which allows to automatically reproduce
experimental data for Majorana neutrino mass models, while keeping the complete
set of the remaining model parameters free for general scans, as necessary in
order to provide reliable predictions for observables outside the neutrino
sector. We provide a proof of this master parametrization and show how to apply
it for several well-known neutrino mass models from the literature. We also
discuss a list of special cases, in which the Yukawa couplings have to fulfill
some particular additional conditions.Comment: 35 pages, 8 figures, 8 tables; v2: minor changes, matches published
versio
Incidence of Anagrus obscurus (Hymenoptera: Mymaridae) egg parasitism on Calopteryx haemorrhoidalis and Platycnemis pennipes (Odonata: Calopterygidae, Platycnemididae) in Italy
Very little is known about the incidence of egg parasitoids in odonates, perhaps because
Odonata eggs are well protected in stems or leaves, sometimes below water. In Central
Italy (Pontecorvo, Frosinone province) two damselflies, Calopteryx haemorrhoidalis
and Platycnemis pennipes occur at high densities. In August 2007 we collected 30 stems
of the aquatic plant Potamogeton sp. used as substrate for oviposition and incubated
eggs in the laboratory. Most stems (24 for C. haemorrhoidalis and 23 for P. pennipes)
contained odonata eggs. Parasitoids emerged from 12 stems, with a mean parasitism of
2% for C. haemorrhoidalis and 6% for P. pennipes, and a maximum of 14% and 50%,
respectively. Furthermore, we observed egg-laying of 19 females of C. haemorrhoidalis
and 11 of P. pennipes, and marked the stems where oviposition was observed. Clutches
remained in the river for 5 days and were then collected and incubated. Parasitoids
emerged from 11 stems out of 30, with an average parasitism of 8% for C.
haemorrhoidalis and 3% for P. pennipes (maximum of 50% and 29%, respectively). All
parasitoids belonged to the family Mymaridae, and were identified as Anagrus
(Anagrus) obscurus Förster, 1861, sensu Soyka, 1955. This is the first time that such
species is described as an egg parasitoid of odonates, and that an egg parasitoid of C.
haemorrhoidalis and P. pennipes is identified. Our data suggest that egg parasitism
might be a significant selective factor for both odonates in the studied locality, affecting
female oviposition behaviour
Variable selection in classification for multivariate functional data
When classification methods are applied to high-dimensional data, selecting a subset of the predictors may lead to an improvement in the predictive ability of the estimated model, in addition to reducing the model complexity. In Functional Data Analysis (FDA), i.e., when data are functions, selecting a subset of predictors corresponds to selecting a subset of individual time instants in the time interval in which the functional data are measured. In this paper, we address the problem of selecting the most informative time instants in multivariate functional data, a case much less studied than its single-variate counterpart. Our proposal allows one to use in a very simple way high-order information of the data, e.g. monotonicity or convexity by means of the functional data derivatives. The aforementioned problem is addressed with tools of Global Optimization in continuous variables: the time instants are selected to maximize the correlation between the class label and the Support Vector Machine score used for classification. The effectiveness of the proposal is shown in univariate and multivariate datasets
Cultura de Calidad y Nivel de Satisfacción de los Estudiantes de Maestría en Docencia Universitaria de la Escuela de Posgrado de la Universidad Nacional de Educación Enrique Guzmán y Valle en el año 2017
La investigación titulada “Cultura de calidad y Nivel de satisfacción en los estudiantes
de la Maestría de Docencia Universitaria de la Escuela de Posgrado de la Universidad
Nacional de Educación Enrique Guzmán y Valle, año 2017”, cuyo propósito principal es
determinar: ¿Cuál es la relación que existe entre la cultura de calidad y los niveles de
satisfacción de los estudiantes de Maestría en Docencia Universitaria de la Escuela de
Posgrado de la Universidad Nacional de Educación “Enrique Guzmán y Valle”, año 2017?
y se formuló el objetivo: Determinar la relación que existe entre la cultura de calidad y el
nivel de satisfacción de los estudiantes de Maestría en Docencia Universitaria de la
Escuela de Posgrado de la Universidad Nacional de Educación “Enrique Guzmán y Valle”,
año 2017. La determinación de la muestra se hizo en base a un muestreo aleatorio simple,
con un tamaño de muestra de 157 estudiantes de los ciclos del periodo de estudios 2017-II
de una población de 228 estudiantes matriculados en el periodo.
Para medir las variables se utilizó el cuestionario según las variables (cultura de
calidad y nivel de satisfacción). Se determinó que el 95% (149) consideran que la cultura
de calidad alto y el 68,2% (107) consideran que es alto el nivel de satisfacción, teniendo
un nivel de significancia p ˂ 0,05 y el Rho de Spearman = +0,416. Por lo cual se puede
inferir que existe una correlación positiva media entre las variables, entonces queda
demostrado que: Existe una relación significativa entre la cultura de calidad y el nivel de
satisfacción en los estudiantes de docencia universitaria de la maestría de la Escuela de
Posgrado de la Universidad Nacional “Enrique Guzmán y Valle” año 2017 (p < 0,05;
2
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Obtenido = 33,170 > ����
2
Teorico =16,919, Rho de Spearman = +0,416 Correlación
positiva media).The research entitled "Culture of quality and Level of satisfaction in the Students of the
Master of University Teaching of the Graduate School of the National University of
Education Enrique Guzman y Valle, year 2017", whose main purpose is to determine:
What Is the relationship between the culture of quality and the levels of satisfaction of the
Students of Master's Degree in University Teaching of the Graduate School of the National
University of Education "Enrique Guzman y Valle", year 2017? and the objective was
formulated: To determine the relationship that exists between the quality culture and the
level of satisfaction of the Students of Master's Degree in University Teaching of the
Graduate School of the National University of Education "Enrique Guzmán y Valle", year
2017. The determination of the sample was made based on a simple random sampling, with
a sample size of 157 students from the cycles of the study period 2017-II from a population
of 228 students enrolled in the period.
To measure the variables, the questionnaire was used according to the variables
(quality culture and level of satisfaction). It was determined that 95% (149) consider the
culture of high quality and 68.2% (107) consider that the level of satisfaction is high,
having a significance level of p ˂ 0.05 and the Rho of Spearman = +0.416. By which it can
be inferred that there is an average positive correlation between the variables, then it has
been demonstrated that: There is a significant relationship between the quality culture and
the level of satisfaction in the university teaching students of the master's degree of the
Graduate School of the National University “Enrique Guzmán y Valle” year 2017 (p <0.05;
X ^ 2 Obtained = 33,170> X ^ 2 Theoretical = 16,919, Rho de Spearman = +0,416
Average positive correlation)
Reflexiones sobre el tópico del ángel del hogar en Adelaida, personaje de Fabla salvaje (1923)
César Vallejo is one of the most representative figures of Peruvian literature and his works have been approached from different perspectives that have been debated until today. Thus, the novel Fabla salvaje, despite its short length, is a complex text that has been read mainly as a representation of identity conflict, dementia or masculinity. In view of this predominance, we consider that an approach to the female character in the novel is necessary in order to generate a reading that dialogues with other aesthetic proposals close to the work. In this sense, the present work will dialogue with the nineteenthcentury cliché of the «angel of the home», which is present in pictorial and literary art and which constitutes a stereotype of the role of women in society. The aim is to recognise the differences and similarities in the conformation of this cliché in Adelaide and Lucia, characters in Fabla salvaje and Aves sin nido, respectively.César Vallejo es una de las figuras más representativas de la literatura peruana y sus obras han sido abordadas desde distintas perspectivas que se han ido debatiendo hasta hoy. De este modo, la novela Fabla salvaje, pese a su corta extensión, es un texto complejo que ha sido leído principalmente como una representación del conflicto de identidad, la demencia o la masculinidad. En vista de esta predominancia, consideramos que la aproximación al personaje femenino en la novela es necesaria para generar una lectura que dialogue con otras propuestas estéticas cercanas a la obra. En ese sentido, el presente trabajo dialogará con el tópico decimonónico del «ángel del hogar» que se encuentra presente en el arte pictórico y literario y que constituye un estereotipo sobre el papel de las mujeres en la sociedad. El objetivo será reconocer las diferencias y las similitudes que presenta la conformación de dicho tópico en Adelaida y Lucía, personajes de Fabla salvaje y Aves sin nido, respectivamente
El miedo y las portadas del diario Trome en tiempos de pandemia (marzo-mayo 2020)
Esta investigación es un estudio de caso que busca entender el papel del miedo en la temática informativa de las portadas del periódico más leído del Perú, el diario Trome, tras el estallido de la epidemia de la Covid-19 en el país, cuando la OMS reconoció que la enfermedad era causada por el nuevo coronavirus SARS-CoV-2. Con base en el análisis cualitativo del contenido, se estudia la utilización del miedo como eje temático, a partir de elementos periodísticos informativos (fuentes, el primer nivel de lectura y la fotografía) y su relación con las propuestas teóricas de varios autores. El trabajo concluye que las noticias destacadas en los primeros meses de la crisis enfatizaron en lo emotivo, destacado en carátulas, titulares y fotos sensacionales y sensacionalistas, con el objetivo de impactar en el público pese a que en ciertos casos los contenidos no se ajustaban a la información oficial
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