251 research outputs found
Los fundamentos matemáticos: teoría de las finanzas
Para aquellos estudiosos de las finanzas provenientes de áreas diferentes de la Economía es muy importante el que conozcan las relaciones entre la Teoría Económica de la Elección y las Finanzas. La Teoría de la Elección sirve no solamente de un marco teórico donde inclusive el matemático más formal y estricto puede sentirse a gusto, sino que también, con ciertos ajustes, es una teoría matemática en el sentido estricto.Este artículo presenta los aspectos básicos de la relación de esta teoría con las finanzas, desde el punto de vista discreto y determinístico. Éste es un primer paso en la conformación de bases teóricas sólidas que permitan no sólo entender las modernas teorías financieras sino también analizar la conveniencia de esas teorías y modelos para explicar los fenómenos financieros de nuestra región.For those approaching Finance from backgrounds different from Economics it is very important to know the relation between Finance and the Economic Theory of Choice. Theory of Choice acts not only as a theoretical frame where even the more strict and formal mathematicians can feel comfortable within, but also (with some adjustments) as a theory in the true mathematical sense. This article, which presents the basic relations between Theory of Choice and Finance, from the discrete-deterministic point of view, is a first step in the construction of solid theoretical foundations that will allow us to understand modern finance literature as well as to analyze the fitness of modern theories and models for our regional financial world
Las ideas básicas de la valoración de opciones a través del modelo binomial
Aunque el estudio de los modelos matemáticos utilizados en la valoración de opciones requiere de una buena preparación en procesos estocásticos continuos y ecuaciones diferenciales estocásticas, las ideas fundamentales detrás de esas representaciones se pueden desarrollar a través de una representación más sencilla, discreta, y con unos requerimientos mínimos de distribuciones de probabilidad. Esta situación se realiza a través de modelos que son una representación de la realidad que, como tal, es sólo una aproximación, haciendo abstracción de algunas de las características observadas, que no se consideran importantes, para resaltar otros aspectos que sí se consideran relevantes.Even though the study of mathematical models used in the pricing of financial options requires a good background in continuous stochastic processes and stochastic differential equations, the basic ideas behind these models can be discussed using a simpler discrete representation with minimal requirements from probability distribution theory. In this case, the models are representing reality and as such, they are aproximation, abstracting out some of the observed features which are not so important, to point out other aspects that are cosidered important
Predictive Pati-Salam theory of fermion masses and mixing
We propose a Pati-Salam extension of the standard model incorporating a
flavor symmetry based on the group. The theory
realizes a realistic Froggatt-Nielsen picture of quark mixing and a predictive
pattern of neutrino oscillations. We find that, for normal neutrino mass
ordering, the atmospheric angle must lie in the higher octant, CP must be
violated in oscillations, and there is a lower bound for the
decay rate. For the case of inverted mass ordering, we find that the lower
atmospheric octant is preferred, and that CP can be conserved in oscillations.
Neutrino masses arise from a low-scale seesaw mechanism, whose messengers can
be produced by a portal at the LHC.Comment: 28 pages, 3 figures, published versio
Crecimiento de renovales de Drimys winteri después de 16 años de aplicados distintos tratamientos de raleo en las cordilleras de los andes y de la costa en Chile
Secondary Drimys winteri forests are among the most common and productive forests in south-central Chile. However, their management has been scarce or many times inadequate due to lack of silvicultural knowledge. In 1986 and 1990 three field experiments were installed; one in the Coastal range of the province of Ranco (40° 09' S) and two in the Andean range of the province of Llanquihue (41° 30' S), to evaluate the effects of different intensities of thinning on the growth and mortality of 28-year-old Drimys winteri secondary forests. After 16 and 10 years of evaluation, great differences were observed among treatments within and between the three experiments. In Hueicoya (Coastal Range) plots thinned at a distance of 3 m had the highest productivity. In Lenca A (Andean Range) the high mortality rates due to windfalls in the plots with trees spaced at 3 and 4 m caused the control plots to have the highest productivity rates. In Lenca B (Andean Range) plots thinned at 2.5 m distance between trees had no significant differences with control plots. At an equal thinning intensity the responses were very different among experiments. We discuss that site quality, residual composition, exposure to winds and rooting characteristics may have influenced these results. In general, it is recommended to thin at 25-45% residual densities (2-3 m distance between trees at the age of thinning of 9-12 cm quadratic stand diameter), but always depending on the risk of windfall
Las ideas básicas de la valoración de opciones a través del modelo binomial
Even though the study of mathematical models used in the pricing of financial options requires a good background in continuous stochastic processes and stochastic differential equations, the basic ideas behind these models can be discussed using a simpler discrete representation with minimal requirements from probability distribution theory. In this case, the models are representing reality and as such, they are aproximation, abstracting out some of the observed features which are not so important, to point out other aspects that are cosidered important.Aunque el estudio de los modelos matemáticos utilizados en la valoración de opciones requiere de una buena preparación en procesos estocásticos continuos y ecuaciones diferenciales estocásticas, las ideas fundamentales detrás de esas representaciones se pueden desarrollar a través de una representación más sencilla, discreta, y con unos requerimientos mínimos de distribuciones de probabilidad. Esta situación se realiza a través de modelos que son una representación de la realidad que, como tal, es sólo una aproximación, haciendo abstracción de algunas de las características observadas, que no se consideran importantes, para resaltar otros aspectos que sí se consideran relevantes
Los fundamentos matemáticos: teoría de las finanzas
For those approaching Finance from backgrounds different from Economics it is very important to know the relation between Finance and the Economic Theory of Choice. Theory of Choice acts not only as a theoretical frame where even the more strict and formal mathematicians can feel comfortable within, but also (with some adjustments) as a theory in the true mathematical sense. This article, which presents the basic relations between Theory of Choice and Finance, from the discrete-deterministic point of view, is a first step in the construction of solid theoretical foundations that will allow us to understand modern finance literature as well as to analyze the fitness of modern theories and models for our regional financial world.Para aquellos estudiosos de las finanzas provenientes de áreas diferentes de la Economía es muy importante el que conozcan las relaciones entre la Teoría Económica de la Elección y las Finanzas. La Teoría de la Elección sirve no solamente de un marco teórico donde inclusive el matemático más formal y estricto puede sentirse a gusto, sino que también, con ciertos ajustes, es una teoría matemática en el sentido estricto.Este artículo presenta los aspectos básicos de la relación de esta teoría con las finanzas, desde el punto de vista discreto y determinístico. Éste es un primer paso en la conformación de bases teóricas sólidas que permitan no sólo entender las modernas teorías financieras sino también analizar la conveniencia de esas teorías y modelos para explicar los fenómenos financieros de nuestra región
The effect of composite resonances on EWPT and Higgs decay into two photons
In the context of strongly coupled electroweak symmetry breaking,
heavy composite particles of different spin and parity may arise and cause observable effects at loop levels. We use an effective chiral Lagrangian to describe the
interactions amongst these composite resonances and the SM fields. We study the
effects of the composite particles on the Higgs decay into two photons and on the
oblique T and S parameters. Consistency with the T and S parameters and the
newly observed Higgs decay into γγ can be found, for axial vector masses in the
range 1.7 TeV MA 2 TeV and vector masses ∼ 0.8MA, provided a non-standard
kinetic mixing between the W3 and B0 fields is included
Detección de anticuerpos séricos contra Toxoplasma gondii (Nicolle y Manceaux, 1909) en llamas (Lama glama Linneaus, 1758) y alpacas (Lama pacos Linneaus, 1758 ) de Chile.
Sera samples from 113 Ilamas (Lama glama) and 127 alpacas (Lama pacos) from the IX and V Regions, respectively, of Chile were tested for Toxoplasma gondii antibodies. The modified agglutination test (MAT) was used in both species and titers 1:25 were considered diagnostically significant based in previously published data. Sera from 49 lamas (43.3%) and 15 alpacas (11.8%) were positive to T. gondii. Percentaje seropositivity in serum dilutions of 1:25, 1:50, 1:500 and 1:5000 was 17.6%; 7.9%; 14.1% and 3.5% in lamas and 0%; 2.3%; 0.7% and 8.6% in alpacas, respectively. The rather low prevalence in alpacas may be associated with geographical conditions, management practices or contacts with cats rather than different species susceptibility. As expected, older animals showed higher reactivity of T. gondii than young animals.Se obtuvieron 113 sueros de llamas y 127 de alpacas de criaderos ubicados en la IX y V Regiones del país respectivamente para determinar la presencia de infección de T. gondii. Para el análisis de los sueros se utilizó el "test" modificado de aglutinación (MAT) a diluciones 1:25; 1:50, 1:500; 1:5000. Del total de 113 sueros de llamas estudiados 49 (43,3%) de ellas presentaron anticuerpos contra T. gondii, mientras que en las alpacas 15 de las 127 (11,8%) fueron positivas. El número de animales positivos en las diluciones 1/25; 1/50; 1/500; 1/5000 fue de 20 (17,6%); 9 (7,9%); 16 (10,6%); 4 (3,5%) en las llamas, respectivamente. En las alpacas los valores fueron de 0 (0%); 3 (2,3%); 1 (0,7%); 11 (8,6%), respectivamente. Aunque no existen antecedentes clínicos de la infección en los establecimientos estudiados, su potencial implicancia en este tipo de patología debería ser considerada a base de los resultados del presente trabajo que demuestra que llamas y alpacas del centro-sur de Chile son reaccionantes a la infección por T. gondii
Top quark effects in composite vector pair production at the LHC
In the context of a strongly coupled Electroweak Symmetry Breaking, composite
light scalar singlet and composite triplet of heavy vectors may arise from an
unspecified strong dynamics and the interactions among themselves and with the
Standard Model gauge bosons and fermions can be described by a Effective Chiral Lagrangian. In this framework, the
production of the and final states at the LHC by
gluon fusion mechanism is studied in the region of parameter space consistent
with the unitarity constraints in the elastic channel of longitudinal gauge
boson scattering and in the inelastic scattering of two longitudinal Standard
Model gauge bosons into Standard Model fermions pairs. The expected rates of
same-sign di-lepton and tri-lepton events from the decay of the
final state are computed and their corresponding backgrounds are estimated. It
is of remarkable relevance that the final state can only be
produced at the LHC via gluon fusion mechanism since this state is absent in
the Drell-Yan process. It is also found that the final state
production cross section via gluon fusion mechanism is comparable with the
Drell-Yan production cross section. The comparison of the
and total cross sections will be crucial for
distinguishing the different models since the vector pair production is
sensitive to many couplings. This will also be useful to determine if the heavy
vectors are only composite vectors or are gauge vectors of a spontaneously
broken gauge symmetry.Comment: 18 pages, 5 tables, 6 figures. Missing figures added. Matches
published versio
Comparative pan-genome analysis of Piscirickettsia salmonis reveals genomic divergences within genogroups
Indexación: Scopus.Piscirickettsia salmonis is the etiological agent of salmonid rickettsial septicemia, a disease that seriously affects the salmonid industry. Despite efforts to genomically characterize P. salmonis, functional information on the life cycle, pathogenesis mechanisms, diagnosis, treatment, and control of this fish pathogen remain lacking. To address this knowledge gap, the present study conducted an in silico pan-genome analysis of 19 P. salmonis strains from distinct geographic locations and genogroups. Results revealed an expected open pan-genome of 3,463 genes and a core-genome of 1,732 genes. Two marked genogroups were identified, as confirmed by phylogenetic and phylogenomic relationships to the LF-89 and EM-90 reference strains, as well as by assessments of genomic structures. Different structural configurations were found for the six identified copies of the ribosomal operon in the P. salmonis genome, indicating translocation throughout the genetic material. Chromosomal divergences in genomic localization and quantity of genetic cassettes were also found for the Dot/Icm type IVB secretion system. To determine divergences between core-genomes, additional pan-genome descriptions were compiled for the so-termed LF and EM genogroups. Open pan-genomes composed of 2,924 and 2,778 genes and core-genomes composed of 2,170 and 2,228 genes were respectively found for the LF and EM genogroups. The core-genomes were functionally annotated using the Gene Ontology, KEGG, and Virulence Factor databases, revealing the presence of several shared groups of genes related to basic function of intracellular survival and bacterial pathogenesis. Additionally, the specific pan-genomes for the LF and EM genogroups were defined, resulting in the identification of 148 and 273 exclusive proteins, respectively. Notably, specific virulence factors linked to adherence, colonization, invasion factors, and endotoxins were established. The obtained data suggest that these genes could be directly associated with inter-genogroup differences in pathogenesis and host-pathogen interactions, information that could be useful in designing novel strategies for diagnosing and controlling P. salmonis infection. © 2017 Nourdin-Galindo, Sánchez, Molina, Espinoza-Rojas, Oliver, Ruiz, Vargas-Chacoff, Cárcamo, Figueroa, Mancilla, Maracaja-Coutinho and Yañez.https://www.frontiersin.org/articles/10.3389/fcimb.2017.00459/ful
- …