Novas tecnologias x instrumento rotatório convencional: avaliação das variáveis que podem interferir no estado emocional da criança

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento da microbiota oral de bebês: análise longitudinal por pirosequenciamento da microbiota de bebês e suas mães dentro de um Programa de Saúde Bucal para Primeira Infância

Pós-graduação em Biopatologia Bucal - ICT

A panchromatic view of the evolution of supermassive black holes

This PhD Thesis is devoted to the accurate analysis of the physical properties of Active Galactic Nuclei (AGN) and the AGN/host-galaxy interplay. Due to the broad-band AGN emission (from radio to hard X-rays), a multi-wavelength approach is mandatory. Our research is carried out over the COSMOS field, within the context of the XMM-Newton wide-field survey. To date, the COSMOS field is a unique area for comprehensive multi-wavelength studies, allowing us to define a large and homogeneous sample of QSOs with a well-sampled spectral coverage and to keep selection effects under control. Moreover, the broad-band information contained in the COSMOS database is well-suited for a detailed analysis of AGN SEDs, bolometric luminosities and bolometric corrections. In order to investigate the nature of both obscured (Type-2) and unobscured (Type-1) AGN, the observational approach is complemented with a theoretical modelling of the AGN/galaxy co-evolution. The X-ray to optical properties of an X-ray selected Type-1 AGN sample are discussed in the first part. The relationship between X-ray and optical/UV luminosities, parametrized by the spectral index αox, provides a first indication about the nature of the central engine powering the AGN. Since a Type-1 AGN outshines the surrounding environment, it is extremely difficult to constrain the properties of its host-galaxy. Conversely, in Type-2 AGN the host-galaxy light is the dominant component of the optical/near-IR SEDs, severely affecting the recovery of the intrinsic AGN emission. Hence a multi-component SED-fitting code is developed to disentangle the emission of the stellar populationof the galaxy from that associated with mass accretion. Bolometric corrections, luminosities, stellar masses and star-formation rates, correlated with the morphology of Type-2 AGN hosts, are presented in the second part, while the final part concerns a physically-motivated model for the evolution of spheroidal galaxies with a central SMBH. The model is able to reproduce two important stages of galaxy evolution, namely the obscured cold-phase and the subsequent quiescent hot-phase.

A comparison of risky sexual behaviors between older and younger men who have sex with men in Houston, TX

Objectives. This study estimated the prevalence of risky sexual behaviors of older (≥ years old) and younger (18-24 years) men who have sex with men (MSM) in Houston, TX and compared the prevalence of these behaviors between the two age cohorts. ^ Methods. Data used in this analysis were from the third MSM cycle of the National HIV Behavioral Surveillance Study. There were 80 older and 119 younger MSM who met the eligibility criteria. Bivariate and Multivariate analysis were performed to compare risky sexual behaviors from the past 12 months and at last sexual encounter between the two age cohorts. ^ Results. OMSM were more likely to be Non-Hispanic White (AOR=4.17; CI: 1.46, 11.89), to have a household income last year greater than $75,000 (AOR=3.59; CI: 1.12, 11.55), and to self-report HIV-positive (AOR=7.35; CI: 2.69, 20.10) than YMSM. OMSM were less like to have had anal sex (AOR=0.11; CI: 0.04, 0.29) or a main sex partner (AOR=0.2; CI: 0.09, 0.45) than YMSM in the past 12 months. Among MSM who had anal sex at last sexual encounter, OMSM were more likely to have not used a condom the entire time regardless of partner type (AOR=3.64; CI: 1.54, 8.61), not used a condom the entire time with a causal sex partner (AOR=7.72; CI: 1.76, 33.92), had unprotected insertive anal intercourse (AOR=2.92; CI: 1.1, 7.75), and used alcohol before or during sex (AOR=5.33; CI: 2.15, 13.2) than YMSM. YMSM and OMSM did not different significantly in knowledge of last sex partner's HIV status. ^ Conclusions. This is not a homogeneous sample of OMSM and risky sexual behaviors vary within the group. There were many similarities in risk behavior between OMSM and YMSM but also some key differences in partner type and condom use indicating a need for increased age-appropriate health promotion programs to limit a potential increase in HIV infection among OMSM. ^

The many lives of magnetized neutron stars

The magnetic field strength at birth is arguably one of the most important properties to determine the evolutionary path of a neutron star. Objects with very high fields, collectively known as magnetars, are characterized by high X-ray quiescent luminosities, occurrence of outbursts, and, for some of them, sporadic giant flares. While the magnetic field strength is believed to drive their collective behaviour, however, the diversity of their properties, and, especially, the observation of magnetar-like bursts from “low-field” pulsars, has been a theoretical puzzle. In this review, we discuss results of long-term simulations following the coupled evolution of the X-ray luminosity and the timing properties for a large, homogeneous sample of X-ray emitting isolated neutron stars, accounting for a range of initial magnetic field strengths, envelope compositions, and neutron star masses. In addition, by following the evolution of magnetic stresses within the neutron star crust, we can also relate the observed magnetar phenomenology to the physical properties of neutron stars, and in particular to their age and magnetic field strength and topology. The dichotomy of “high-B” field pulsars versus magnetars is naturally explained, and occasional outbursts from old, low B-field neutron stars are predicted. We conclude by speculating on the fate of old magnetars, and by presenting observational diagnostics of the neutron star crustal field topology.

Minority dissent and team innovation:the importance of participation in decision making

This study integrates research on minority dissent and individual creativity, as well as team diversity and the quality of group decision making, with research on team participation in decision making. From these lines of research, it was proposed that minority dissent would predict innovation in teams but only when teams have high levels of participation in decision making. This hypothesis was tested in 2 studies, 1 involving a homogeneous sample of self-managed teams and 1 involving a heterogeneous sample of cross-functional teams. Study 1 suggested that a newly developed scale to measure minority dissent has discriminant validity. Both Study 1 and Study 2 showed more innovations under high rather than low levels of minority dissent but only when there was a high degree of participation in team decision making. It is concluded that minority dissent stimulates creativity and divergent thought, which, through participation, manifest as innovation.

Influencia de los agentes directos e indirectos en la participación físico-deportiva extraescolar del alumnado de la ESO

[ES]El presente estudio pretende conocer cómo influye el contexto inmediato de los adolescentes de la ESO en su motivación hacia la participación en una actividad físico-deportiva en su tiempo libre. Para ello, se ha seleccionado una muestra homogénea para los diferentes géneros en la que participan dos grupos por nivel educativo de la ESO. Para obtener los resultados se diseñó un cuestionario aportando como resultado referencial que la mayor influencia sobre los adolescentes se debe a la existencia de entornos cercanos de práctica y al disfrute por su desarrollo, apreciándose pequeñas diferencias en las influencias si se divide a la muestra por edad o género.

Montreal Cognitive Assessment (MoCA): validation study for vascular dementia

The Montreal Cognitive Assessment (MoCA) is a brief instrument developed for the screening of milder forms of cognitive impairment, having surpassed the well-known limitations of the MMSE. The aim of the present study was to validate the MoCA as well as its short version, which was proposed by the NINDS-CSN VCI Harmonization Standards for screening Vascular Dementia (VaD) patients. The results, based on a homogeneous sample of 34 VaD patients, indicate that the MoCA is a psychometrically valid and reliable instrument for cognitive screening in VaD patients, showing excellent discriminant validity. Both the full and short versions of the MoCA had excellent diagnostic accuracy in discriminating VaD patients, exhibiting an area under curve (AUC) higher than the MMSE [AUC(MoCA full version) = .950; 95% IC = .868-.988; AUC(MoCA short version) = .936; 95% IC = .849-.981; AUC(MMSE) = .860; 95% IC = .754-.932]. With a cutoff below 17 on the MoCA full version and 8 on the short version, the results for sensitivity, specificity, positive and negative predictive values, and classification accuracy were superior compared to the MMSE. In conclusion, both versions of the MoCA are valid, reliable, sensitive and accurate screening instruments for VaD patients.

Unveiling the unknown of cool stars with high-resolution spectroscopy

Cool giant and supergiant stars are among the brightest populations in any stellar system and they are easily observable out to large distances, especially at infrared wavelengths. These stars also dominate the integrated light of star clusters in a wide range of ages, making them powerful tracers of stellar populations in more distant galaxies. High-resolution near-IR spectroscopy is a key tool for quantitatively investigating their kinematic, evolutionary and chemical properties. However, the systematic exploration and calibration of the NIR spectral diagnostics to study these cool stellar populations based on high-resolution spectroscopy is still in its pioneering stage. Any effort to make progress in the field is innovative and of impact on stellar archaeology and stellar evolution. This PhD project takes the challenge of exploring that new parameter space and characterizing the physical properties, the chemical content and the kinematics of cool giants and supergiants in selected disc fields and clusters of our Galaxy, with the ultimate goal of tracing their past and recent star formation and chemical enrichment history. By using optical HARPS-N and near-infrared GIANO-B high-resolution stellar spectra in the context of the large program SPA-Stellar Population Astrophysics: the detailed, age-resolved chemistry of the Milky Way disk” (PI L. Origlia), an extensive study of Arcturus, a standard calibrator for red giant stars, has been performed. New diagnostics of stellar parameters as well as optimal linelists for chemical analysis have been provided. Then, such diagnostics have been used to determine evolutionary properties, detailed chemical abundances of almost 30 different elements and mixing processes of a homogeneous sample of red supergiant stars in the Perseus complex.

A mathematical model for estimating the extent of solute- and water-flux heterogeneity in multiple sample percolation experiments

Multiple sampling is widely used in vadose zone percolation experiments to investigate the extent in which soil structure heterogeneities influence the spatial and temporal distributions of water and solutes. In this note, a simple, robust, mathematical model, based on the beta-statistical distribution, is proposed as a method of quantifying the magnitude of heterogeneity in such experiments. The model relies on fitting two parameters, alpha and zeta to the cumulative elution curves generated in multiple-sample percolation experiments. The model does not require knowledge of the soil structure. A homogeneous or uniform distribution of a solute and/or soil-water is indicated by alpha = zeta = 1, Using these parameters, a heterogeneity index (HI) is defined as root 3 times the ratio of the standard deviation and mean. Uniform or homogeneous flow of water or solutes is indicated by HI = 1 and heterogeneity is indicated by HI > 1. A large value for this index may indicate preferential flow. The heterogeneity index relies only on knowledge of the elution curves generated from multiple sample percolation experiments and is, therefore, easily calculated. The index may also be used to describe and compare the differences in solute and soil-water percolation from different experiments. The use of this index is discussed for several different leaching experiments. (C) 1999 Elsevier Science B.V. All rights reserved.

Sample-induced RF perturbations in high-field, high-resolution NMR spectroscopy

Conducting dielectric samples are often used in high-resolution experiments at high held. It is shown that significant amplitude and phase distortions of the RF magnetic field may result from perturbations caused by such samples. Theoretical analyses demonstrate the spatial variation of the RF field amplitude and phase across the sample, and comparisons of the effect are made for a variety of sample properties and operating field strengths. Although the effect is highly nonlinear, it tends to increase with increasing field strength, permittivity, conductivity, and sample size. There are cases, however, in which increasing the conductivity of the sample improves the homogeneity of the amplitude of the RF field across the sample at the expense of distorted RF phase. It is important that the perturbation effects be calculated for the experimental conditions used, as they have the potential to reduce the signal-to-noise ratio of NMR experiments and may increase the generation of spurious coherences. The effect of RF-coil geometry on the coherences is also modeled, with the use of homogeneous resonators such as the birdcage design being preferred, Recommendations are made concerning methods of reducing sample-induced perturbations. Experimental high-field imaging and high-resolution studies demonstrate the effect. (C) 1997 Academic Press.

Discrete time Non-homogeneous Semi-Markov Processes applied to Models for Disability Insurance

In this paper, we present a stochastic model for disability insurance contracts. The model is based on a discrete time non-homogeneous semi-Markov process (DTNHSMP) to which the backward recurrence time process is introduced. This permits a more exhaustive study of disability evolution and a more efficient approach to the duration problem. The use of semi-Markov reward processes facilitates the possibility of deriving equations of the prospective and retrospective mathematical reserves. The model is applied to a sample of contracts drawn at random from a mutual insurance company.

Latent Class Analysis of Gambling Activities in a Sample of Young Swiss Men : Association with Gambling Problems, Substance Use Outcomes, Personality Traits and Coping Strategies.

The study aimed to identify different patterns of gambling activities (PGAs) and to investigate how PGAs differed in gambling problems, substance use outcomes, personality traits and coping strategies. A representative sample of 4989 young Swiss males completed a questionnaire assessing seven distinct gambling activities, gambling problems, substance use outcomes, personality traits and coping strategies. PGAs were identified using latent class analysis (LCA). Differences between PGAs in gambling and substance use outcomes, personality traits and coping strategies were tested. LCA identified six different PGAs. With regard to gambling and substance use outcomes, the three most problematic PGAs were extensive gamblers, followed by private gamblers, and electronic lottery and casino gamblers, respectively. By contrast, the three least detrimental PGAs were rare or non-gamblers, lottery only gamblers and casino gamblers. With regard to personality traits, compared with rare or non-gamblers, private and casino gamblers reported higher levels of sensation seeking. Electronic lottery and casino gamblers, private gamblers and extensive gamblers had higher levels of aggression-hostility. Extensive and casino gamblers reported higher levels of sociability, whereas casino gamblers reported lower levels of anxiety-neuroticism. Extensive gamblers used more maladaptive and less adaptive coping strategies than other groups. Results suggest that gambling is not a homogeneous activity since different types of gamblers exist according to the PGA they are engaged in. Extensive gamblers, electronic and casino gamblers and private gamblers may have the most problematic PGAs. Personality traits and coping skills may predispose individuals to PGAs associated with more or less negative outcomes.

Homogeneous Assays for Simplified Screening of HLA-conferred Genetic Disease Risk

The increasing incidence of type 1 diabetes has led researchers on a quest to find the reason behind this phenomenon. The rate of increase is too great to be caused simply by changes in the genetic component, and many environmental factors are under investigation for their possible contribution. These studies require, however, the participation of those individuals most likely to develop the disease, and the approach chosen by many is to screen vast populations to find persons with increased genetic risk factors. The participating individuals are then followed for signs of disease development, and their exposure to suspected environmental factors is studied. The main purpose of this study was to find a suitable tool for easy and inexpensive screening of certain genetic risk markers for type 1 diabetes. The method should be applicable to using whole blood dried on sample collection cards as sample material, since the shipping and storage of samples in this format is preferred. However, the screening of vast sample libraries of extracted genomic DNA should also be possible, if such a need should arise, for example, when studying the effect of newly discovered genetic risk markers. The method developed in this study is based on homogeneous assay chemistry and an asymmetrical polymerase chain reaction (PCR). The generated singlestranded PCR product is probed by lanthanide-labelled, LNA (locked nucleic acid)-spiked, short oligonucleotides with exact complementary sequences. In the case of a perfect match, the probe is hybridised to the product. However, if even a single nucleotide difference occurs, the probe is bound instead of the PCR product to a complementary quencher-oligonucleotide labelled with a dabcyl-moiety, causing the signal of the lanthanide label to be quenched. The method was applied to the screening of the well-known type 1 diabetes risk alleles of the HLA-DQB1 gene. The method was shown to be suitable as an initial screening step including thousands of samples in the scheme used in the TEDDY (The Environmental Determinants of Diabetes in the Young) study to identify those individuals at increased genetic risk. The method was further developed into dry-reagent form to allow an even simpler approach to screening. The reagents needed in the assay were in dry format in the reaction vessel, and performing the assay required only the addition of the sample and, if necessary, water to rehydrate the reagents. This allows the assay to be successfully executed even by a person with minimal laboratory experience.

RAPID AND SENSITIVE DETERMINATION OF PALLADIUM USING HOMOGENEOUS LIQUID-LIQUID MICROEXTRACTION VIA FLOTATION ASSISTANCE FOLLOWED BY GRAPHITE FURNACE ATOMIC ABSORPTION SPECTROMETRY

A method for the determination of trace amounts of palladium was developed using homogeneous liquid-liquid microextraction via flotation assistance (HLLME-FA) followed by graphite furnace atomic absorption spectrometry (GFAAS). Ammonium pyrrolidine dithiocarbamate (APDC) was used as a complexing agent. This was applied to determine palladium in three types of water samples. In this study, a special extraction cell was designed to facilitate collection of the low-density solvent extraction. No centrifugation was required in this procedure. The water sample solution was added to the extraction cell which contained an appropriate mixture of extraction and homogeneous solvents. By using air flotation, the organic solvent was collected at the conical part of the designed cell. Parameters affecting extraction efficiency were investigated and optimized. Under the optimum conditions, the calibration graph was linear in the range of 1.0-200 µg L-1 with a limit of detection of 0.3 µg L-1. The performance of the method was evaluated for the extraction and determination of palladium in water samples and satisfactory results were obtained. In order to verify the accuracy of the approach, the standard addition method was applied for the determination of palladium in spiked synthetic samples and satisfactory results were obtained.