Multifractal analysis with the probability density function at the three-dimensional Anderson transition

The probability density function (PDF) for critical wavefunction amplitudes is studied in the three-dimensional Anderson model. We present a formal expression between the PDF and the multifractal spectrum f(alpha) in which the role of finite-size corrections is properly analyzed. We show the non-gaussian nature and the existence of a symmetry relation in the PDF. From the PDF, we extract information about f(alpha) at criticality such as the presence of negative fractal dimensions and we comment on the possible existence of termination points. A PDF-based multifractal analysis is hence shown to be a valid alternative to the standard approach based on the scaling of general inverse participation ratios.Comment: 4 pages, 7 figure

Seeing The Solar Corona in Three Dimensions

The large availability and rich spectral coverage of today’s observational data of the solar corona, and the high spatial and temporal resolution provided by many instruments, has enabled the evolution of three-dimensional (3D) physical models to a great level of detail. However, the 3D information provided by the data is rather limited as every instrument observes from a single angle of vision, or two at the most in the case of the STEREO mission. Two powerful available observational techniques to infer detailed 3D information of the solar corona from empirical data are stereoscopy and tomography. In particular, the technique known as differential emission measure tomography (DEMT) allows determination of the 3D distribution of the coronal electron density and temperature in the inner corona. This paper summarizes the main technical aspects of DEMT, reviews all published work based on it, and comments on its future development and applications.Fil: Vasquez, Alberto Marcos. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentin

Effect od frequency of sucrose exposure on dental biofilm composition and anamel demineralization in the presence of fluoride

Orientador: Cinthia Pereira Machado TabchouryDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: Nos últimos anos tem sido sugerido que a freqüência de consumo de açúcares poderia ser incrementada, se fluoreto (F) a partir da água ou dentifrício fosse utilizado. Mas o seu efeito na desmineralização do esmalte e principalmente na composição do biofilme dental formado sob várias freqüências de consumo de açúcares não foi totalmente explorado. Desta forma, o objetivo deste estudo foi avaliar, na presença do uso de fluoreto, o efeito da freqüência de exposição à sacarose na composição microbiológica e bioquímica do biofilme dental e sua relação com a desmineralização do esmalte dental. Dez voluntários adultos saudáveis, vivendo em uma área fluoretada, usaram dispositivos intra-orais palatinos contendo 4 blocos de esmalte dental hígido humano, durante 3 fases experimentais de 14 dias cada. Os voluntários escovaram seus dentes usando dentifrício fluoretado, contendo 1100 ppm de F na forma de NaF, 3 vezes ao dia. Foram avaliadas as seguintes freqüências de exposição à solução de sacarose 20%: O ( controle), 2, 4, 6, 8 e 10 vezes/dia. Em cada fase experimental, foram testadas 2 freqüências (0-2, 4-6, 8-10). Ao final de cada fase experimental, o biofilme dental foi coletado, os blocos de esmalte foram removidos dos dispositivos e foram realizadas as seguintes análises: contagem de microrganismos totais (MT), estreptococos totais (ET), estreptococos do grupo mutans (EM) e lactobacilos (LB); porcentagem de estreptococos do grupo mutans em relação a microrganismos totais (%EM/MT) e estreptococos totais (%EM/ET); porcentagem de lactobacilos em relação a microrganismos totais (%LB/MT); determinação da quantidade de polissacarídeo extracelular (PEC) e intracelular (PIC); análise da concentração de íQns F, cálcio (Ca) e fósforo inorgânico (Pi) no estroma e fluido do biofilme dental e avaliação de perda mineral do esmalte seccionado longitudinalmente (~Z). Os resultados mostraram perdas minerais (?Z) estatisticamente maiores que o controle (p<0,05) nas freqüências maiores que 6 x/dia. Entretanto, quantidade de biofilme, contagens de MT, ET, LB e concentração de PEC aumentaram, enquanto as concentrações de F, Ca e Pj no estroma diminuíram significativamente (p<0,05), com freqüências de exposição à sacarose menores que 6 x/dia. Em conclusão, F é capaz de reduzir a perda mineral do esmalte dental se o consumo de sacarose não for maior que 6 vezes ao dia, mas mudanças na composição bioquímica e microbiológica do biofilme dental são observadas com menores freqüências de usoAbstract: ln the last years, it has been suggested that the frequency of consumption of sugars could be increased, if fluoride from water or dentifrice is used. However, its effect on enamel demineralization and mainly on composition of dental biofilm formed under various frequencies of consumption of sugars has not been completely explored. Therefore, the objective of this study was to evaluate, in the presence of fluoride, the effect of the frequency of sucrose exposure on the microbiological and biochemical composition of dental biofilm and its relationship with demineralization of dental enamel. Ten healthy adult volunteers, living in a fluoridated area, wore intra-oral palatal appliances containing four sound human dental enamel blocks, during 3 experimental phases of 14 days each. The volunteers brushed their natural teeth with fluoridated dentifrice, containing 1100 ppm of F, in the forro of NaF, 3 times/day. The following frequencies of exposure to 20% sucrose were evaluated: O (control), 2, 4, 6, 8 and 10 times/day. lh each experimental phase, 2 frequencies were tested (0-2, 4-6, 8-10). At the end of each experimental phase, dental biofilm was collected, enamel blocks were removed from the appliance and the following analysis were conducted: counts of total microorganisms (TM), total streptococci (TS), mutans streptococci (MS) and lactobacillus (LB); percentage of mutans streptococci in relation to total microorganisms (%MS/TM) and total streptococci (%MS/TS); percentage of lactobacillus in relation to total microorganisms (%LB/TM)concentration of extracellular (EPS) and intracelular (IPS) polysaccharides; fluoride (F), calcium (Ca), inorganic phosphorus (Pi) concentration in whole biofilm and fluid; and mineral loss of longitudinally sectioned enamel (,:1Z). The results showed significantly higher (p<0.05) minerallosses (?Z) than control group for the frequencies higher than 6 x/day. However, biofilm mass, TM, TS, LB counts and EPS concentration increased, while F, Ca and Pi concentration in the whole biofilm decreased significantly (p<0.05) in the frequencies of sucrose exposure lower than 6 x/day. ln conc1usion, fluoride is able to reduce enamel demineralization if sucrose consumption is not higher than 6 x/day, but changes in the biochemical and microbiological composition of the dental biofilm are observed with lower frequencies of useMestradoCariologiaMestre em Odontologi

Efficient Electromagnetic Modelling of Complex Structures

Part 1. Space vehicles re-entering earth's atmosphere produce a shock wave which in turns results in a bow of plasma around the vehicle body. This plasma signicantly affects all radio links between the vehicle and ground, since the electron plasma frequency reaches beyond several GHz. In this work, a model of the propagation in plasma issue is developed. The radiofrequency propagation from/to antennae installed aboard the vehicle to the ground stations (or Data Relay Satellites) can be predicted, and the position of this antennae improved before a mission launch. Part 2. The Surface Integral Equation is one of the most used methods in the simulation of electromagnetic problems. The method used a discretized description of the surface on which a number of basis functions are needed. In the case of multi-scale structures, the test-object has regions with high details that require a fine mesh, together with flat surfaces where the current can be properly described with a coarser mesh. The goal of this work is to develop an automatic tool that identies the regions to be refined in a initial coarse mesh (dened only by geometry) using electromagnetic characteristics of the problem. It avoid the use of more unknowns that the actually needed (computational cost) and permits use a geometric mesh as base for different problems, adapting to each electromagnetic incidence automatically

Revisão taxonômica e filogenia de Cheirodontinae (Characiformes: Characidae) : integrando evidência morfológica e molecular

A ictiofauna neotropical de água doce é taxonomicamente a mais diversa do planeta, porém sua diversidade ainda é amplamente subestimada. A evidência para essa subestimativa vem do acúmulo de formas morfologicamente distintas, mas não descritas, depositadas em coleções de museus e dos resultados de estudos baseados em DNA (por exemplo, delimitação de espécies) que identificam consistentemente um número maior de linhagens divergentes do que o atualmente é aceito, mesmo dentro de grupos bem estudados. Investigamos a diversidade de linhagens dentro de Cheirodontinae, sequenciamos a subunidade I do citocromo c oxidase mitocondrial (COI) e delineamos linhagens usando 8 diferentes métodos de delimitação de espécies de lócus único. Os resultados fornecem evidências fortes e consistentes para a existência de uma diversidade adicional e não descrita dentro de Cheirodontinae. Dentro de Cheirodontinae, encontramos hipóteses divergentes (morfológicas vs. moleculares) sobre as relações filogenéticas dentro da subfamília. Testamos essas duas hipóteses, usando dados integrados (morfológicos e moleculares: COI, 16S, 12S, RAG1, RAG2, Myh6) propomos uma nova hipótese de relações filogenéticas dentro da subfamília, e subdividimos a subfamília, em 8 clados, que são corroborados pelas diferentes metodologias (parcimônia e modelos). Com esta informação morfológica e molecular, estimamos o tempo de divergência dentro da subfamília usando Evidencia-total com datação FBD, o que nos levou a determinar que Cheirodontinae se diversificou de Aphyocharacinae, aproximadamente 28 Ma. Com esses resultados reconstruímos a história biogeográfica dos Cheirodontinae na região neotropical e testamos a influência do tamanho e sua capacidade de inseminação em sua diversificação.The neotropical freshwater fish fauna is taxonomically the most diverse vertebrate on the planet, however its diversity is still largely underestimated. Evidence for this underestimation comes from the accumulation of morphologically distinct but undescribed forms deposited in museum collections, and from the results of various DNA-based studies (eg, species delimitation) that consistently identify a larger number of divergent lineages than currently accepted, even within well-studied species, we investigated the diversity of lineages within the Cheirodontinae. To investigate this diversity, we sequenced the mitochondrial cytochrome c oxidase subunit I (COI) and delineated lineages using 8 different single-locus species delimitation methods. The results provide strong and consistent evidence for additional and undescribed taxonomic diversity in Cheirodontinae. Within the Cheirodontinae, we find divergent hypotheses (morphological vs. molecular) about phylogenetic relationships within the subfamily. We test these two hypotheses, using integrated data (morphological and molecular: COI, 16S, 12S, RAG1, RAG2, Myh6) we propose a new hypothesis of phylogenetic relationships within the subfamily, and we subdivide the subfamily, into 8 clades, which are corroborated by the different methodologies (parsimony and models). With this morphological and molecular information, we estimated the time of divergence within the subfamily using Total-evidence with FBD dating, this led us to determine that the Cheirodontinae diversified from the Aphyocharacinae, approximately 28 Ma. With these results we reconstruct the biogeographical history of the Cheirodontinae in the neotropical region and we test the influence of the size and its insemination capacity in its diversification

New Physics in Double Higgs Production at Future e+e−e^+ e^- Colliders

We study the effects of new physics in double Higgs production at future $e^+ e^-$ colliders. In the Standard Model the chiral limit ($m_e=0$) plays an important role for this process, being responsible for the smallness of the tree-level diagrams with respect to the 1-loop contributions. In our work, we consider the possibility of an enhancement due to the contribution of Standard Model dimension-six effective operators. We show that there are only two relevant operators for this process that are not yet (strongly) constrained by other data. We perform a sensitivity study on the operator coefficients for several benchmark values of energy and integrated luminosity related to the proposed linear colliders such as CLIC, ILC and FCC-ee and we derive expected 95% CL limits for each benchmark scenario.Comment: 17 pages, 8 figures, 1 table. New references adde

Scaling laws of quiet-Sun coronal loops

We study a series of relations between physical parameters in coronal loops of the quiet Sun reconstructed by combining tomographic techniques and modeling of the coronal magnetic field. We use differential emission measure tomography (DEMT) to determine the three-dimensional distribution of the electron density and temperature in the corona, and we model the magnetic field with a potential-field source-surface (PFSS) extrapolation of a synoptic magnetogram. By tracing the DEMT products along the extrapolated magnetic field lines, we obtain loop-averaged electron density and temperature. Also, loop-integrated energy-related quantities are computed for each closed magnetic field line. We apply the procedure to Carrington rotation 2082, during the activity minimum between Solar Cycles 23 and 24, using data from the Extreme Ultraviolet Imager on board the Solar Terrestrial Relations Observatory (STEREO) spacecraft. We find a scaling law between the loop-average density N and loop length L,Nm∼L-0.35, but we do not find a significant relation between loop-average temperature and loop length. We confirm though the previously found result that loop-average temperatures at the equatorial latitudes are lower than at higher latitudes. We associate this behavior with the presence at the equatorial latitudes of loops with decreasing temperatures along their length (“down” loops), which are in general colder than loops with increasing temperatures (“up” loops). We also discuss the role of “down” loops in the obtained scaling laws of heating flux versus loop length for different heliographic latitudes. We find that the obtained scalings for quiet-Sun loops do not generally agree with those found in the case of AR loops from previous observational and theoretical studies. We suggest that to better understand the relations found, it is necessary to forward model the reconstructed loops using hydrodynamic codes working under the physical conditions of the quiet-Sun corona.Fil: Mac Cormack, Cecilia. Universidad Nacional de Tres de Febrero; Argentina. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Lopez Fuentes, Marcelo Claudio. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Mandrini, Cristina Hemilse. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Lloveras, Diego Gustavo. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Poisson, Mariano. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina. Universidad Nacional de Tres de Febrero; ArgentinaFil: Vasquez, Alberto Marcos. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina. Universidad Nacional de Tres de Febrero; Argentin

CONSTRUCCIÓN Y PROCESOS PSICOMÉTRICOS DE UNA ESCALA DE ACTITUDES FRENTE AL RECICLAJE EN UNIVERSITARIOS PERUANOS 2020

La producción de residuos sólidos se incrementa cada día y afecta al ser humano en todas sus dimensiones, frente a esto se considera que el reciclaje ayuda a la optimización de recursos y reduce la contaminación del medio ambiente. Esta investigación tuvo como objetivo general establecer los procesos psicométricos en la construcción de una escala de actitudes frente al reciclaje en estudiantes de universidades peruanas- 2020. Fue de tipo aplicada, trasversal y tecnológica, con un diseño instrumental; se empleó una muestra de 394 alumnos de diferentes universidades; el instrumento que se utilizó fue la Escala de Actitudes Frente al Reciclaje. Como resultado se obtuvo una validez de contenido con valores de 1.00; en la validez de constructo se obtuvo un KMO de 0.88, y en la matriz de factor rotado sólo fueron validados 18 ítems de los 26 que fueron en la versión inicial; en la validez convergente se encontraron correlaciones significativas de 0.805, 0.829 y 0.389; la confiabilidad total de Omega fue de 0.93 y en sus dimensiones fue de 0.85, 0.81 y 0.83;&nbsp;&nbsp; en cuanto a las normas percentilares a nivel general y por factores, se establecieron&nbsp;&nbsp; cuatro&nbsp; categorías: bajo, promedio bajo, promedio alto&nbsp; y alto. En conclusión, se observó que la escala muestra una adecuada validez y confiabilidad en toda su extensión

Propuesta basada en la resiliencia para mejorar el funcionamiento psicológico positivo en madres de familia del distrito de Curamori- Piura, 2022

Esta investigación tuvo como objetivo elaborar una propuesta basada en la resiliencia para mejorar el funcionamiento psicológico positivo en madres de familia del Distrito de Curamori 2022, fue un trabajo de tipo no experimental de corte transversal con un diseño descriptivo propositivo, la muestra fue de 169 mujeres, se administraron dos instrumentos: la escala de resiliencia y el cuestionario de funcionamiento psicológico positivo, ambas pruebas contaron con adecuadas propiedades psicométricas de validez y confiabilidad. Los resultados indicaron que, el 66,9% de madres de familia presentan bajos y regulares niveles de resiliencia y el 33,1% se encuentra en un nivel alto; se evidenció que el 66,8% de madres tienen bajos y regulares niveles de funcionamiento psicológico y un 33% presenta un buen funcionamiento. Con base en estos resultados se elaboró una propuesta basada en la resiliencia para mejorar el funcionamiento psicológico en esta población, consta de 12 sesiones y se fundamenta en la psicológica positiva. Se concluye que las condiciones de ambas variables necesitan mejorar, por tal razón, el programa que se propone será de mucho beneficio para estas madres de familia