Recent developments in statistical methods for detecting genetic loci affecting phenotypic variability

A number of recent works have introduced statistical methods for detecting genetic loci that affect phenotypic variability, which we refer to as variability-controlling quantitative trait loci (vQTL). These are genetic variants whose allelic state predicts how much phenotype values will vary about their expected means. Such loci are of great potential interest in both human and non-human genetic studies, one reason being that a detected vQTL could represent a previously undetected interaction with other genes or environmental factors. The simultaneous publication of these new methods in different journals has in many cases precluded opportunity for comparison. We survey some of these methods, the respective trade-offs they imply, and the connections between them. The methods fall into three main groups: classical non-parametric, fully parametric, and semi-parametric two-stage approximations. Choosing between alternatives involves balancing the need for robustness, flexibility, and speed. For each method, we identify important assumptions and limitations, including those of practical importance, such as their scope for including covariates and random effects. We show in simulations that both parametric methods and their semi-parametric approximations can give elevated false positive rates when they ignore mean-variance relationships intrinsic to the data generation process. We conclude that choice of method depends on the trait distribution, the need to include non-genetic covariates, and the population size and structure, coupled with a critical evaluation of how these fit with the assumptions of the statistical model.

Non-durable consumption and real-estate prices in Brazil: panel-data analysis at the state level

Housing is an important component of wealth for a typical household in many countries. The objective of this paper is to investigate the effect of real-estate price variation on welfare, trying to close a gap between the welfare literature in Brazil and that in the U.S., the U.K., and other developed countries. Our first motivation relates to the fact that real estate is probably more important here than elsewhere as a proportion of wealth, which potentially makes the impact of a price change bigger here. Our second motivation relates to the fact that real-estate prices boomed in Brazil in the last five years. Prime real estate in Rio de Janeiro and São Paulo have tripled in value in that period, and a smaller but generalized increase has been observed throughout the country. Third, we have also seen a recent consumption boom in Brazil in the last five years. Indeed, the recent rise of some of the poor to middle-income status is well documented not only for Brazil but for other emerging countries as well. Regarding consumption and real-estate prices in Brazil, one cannot imply causality from correlation, but one can do causal inference with an appropriate structural model and proper inference, or with a proper inference in a reduced-form setup. Our last motivation is related to the complete absence of studies of this kind in Brazil, which makes ours a pioneering study. We assemble a panel-data set for the determinants of non-durable consumption growth by Brazilian states, merging the techniques and ideas in Campbell and Cocco (2007) and in Case, Quigley and Shiller (2005). With appropriate controls, and panel-data methods, we investigate whether house-price variation has a positive effect on non-durable consumption. The results show a non-negligible significant impact of the change in the price of real estate on welfare consumption), although smaller then what Campbell and Cocco have found. Our findings support the view that the channel through which house prices affect consumption is a financial one.

The art of being together: a social constructionist perspective on dialogic methods in the organizational context

The purpose of this project is to understand, under a social constructionist approach, what are the meanings that external facilitators and organizational members (sponsors) working with dialogic methods place on themselves and their work. Dialogic methods, with the objective of engaging groups in flows of conversations to envisage and co-create their own future, are growing fast within organizations as a means to achieve collective change. Sharing constructionist ideas about the possibility of multiple realities and language as constitutive of such realities, dialogue has turned into a promising way for transformation, especially in a macro context of constant change and increasing complexity, where traditional structures, relationships and forms of work are questioned. Research on the topic has mostly focused on specific methods or applications, with few attempts to study it in a broader sense. Also, despite the fact that dialogic methods work on the assumption that realities are socially constructed, few studies approach the topic from a social constructionist perspective, as a research methodology per se. Thus, while most existing research aims at explaining whether or how particular methods meet particular results, my intention is to explore the meanings sustaining these new forms of organizational practice. Data was collected through semi-structured interviews with 25 people working with dialogic methods: 11 facilitators and 14 sponsors, from 8 different organizations in Brazil. Firstly, the research findings indicate several contextual elements that seem to sustain the choices for dialogic methods. Within this context, there does not seem to be a clear or specific demand for dialogic methods, but a set of different motivations, objectives and focuses, bringing about several contrasts in the way participants name, describe and explain their experiences with such methods, including tensions on power relations, knowledge creation, identity and communication. Secondly, some central ideas or images were identified within such contrasts, pointing at both directions: dialogic methods as opportunities for the creation of new organizational realities (with images of a ‘door’ or a ‘flow’, for instance, which suggest that dialogic methods may open up the access to other perspectives and the creation of new realities); and dialogic methods as new instrumental mechanisms that seem to reproduce the traditional and non-dialogical forms of work and relationship. The individualistic tradition and its tendency for rational schematism - pointed out by social constructionist scholars as strong traditions in our Western Culture - could be observed in some participants’ accounts with the image of dialogic methods as a ‘gym’, for instance, in which dialogical – and idealized –‘abilities’ could be taught and trained, turning dialogue into a tool, rather than a means for transformation. As a conclusion, I discuss what the implications of such taken-for-granted assumptions may be, and offer some insights into dialogue (and dialogic methods) as ‘the art of being together’.

Studies in non-Gaussian analysis

This thesis presents general methods in non-Gaussian analysis in infinite dimensional spaces. As main applications we study Poisson and compound Poisson spaces. Given a probability measure μ on a co-nuclear space, we develop an abstract theory based on the generalized Appell systems which are bi-orthogonal. We study its properties as well as the generated Gelfand triples. As an example we consider the important case of Poisson measures. The product and Wick calculus are developed on this context. We provide formulas for the change of the generalized Appell system under a transformation of the measure. The L² structure for the Poisson measure, compound Poisson and Gamma measures are elaborated. We exhibit the chaos decomposition using the Fock isomorphism. We obtain the representation of the creation, annihilation operators. We construct two types of differential geometry on the configuration space over a differentiable manifold. These two geometries are related through the Dirichlet forms for Poisson measures as well as for its perturbations. Finally, we construct the internal geometry on the compound configurations space. In particular, the intrinsic gradient, the divergence and the Laplace-Beltrami operator. As a result, we may define the Dirichlet forms which are associated to a diffusion process. Consequently, we obtain the representation of the Lie algebra of vector fields with compact support. All these results extends directly for the marked Poisson spaces.

Non-inclusion complexes between riboflavin and cyclodextrins

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Peat humic substances enriched with nutrients for agricultural applications: Competition between nutrients and non-essential metals present in tropical soils

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A non-invasive method for silencing gene transcription in honeybees maintained under natural conditions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A simple and non-destructive model for individual leaf area estimation in citrus

Introduction. Leaf area is often related to plant growth, development, physiology and yield. Many non-destructive models have been proposed for leaf area estimation of several plant genotypes, demonstrating that leaf length, leaf width and leaf area are closely correlated. Thus, the objective of our study was to develop a reliable model for leaf area estimation from linear measurements of leaf dimensions for citrus genotypes. Materials and methods. Leaves of citrus genotypes were harvested, and their dimensions (length, width and area) were measured. Values of leaf area were regressed against length, width, the square of length, the square of width and the product (length x width). The most accurate equations, either linear or second-order polynomial, were regressed again with a new data set; then the most reliable equation was defined. Results and discussion. The first analysis showed that the variables length, width and the square of length gave better results in second-order polynomial equations, while the linear equations were more suitable and accurate when the width and the product (length x width) were used. When these equations were regressed with the new data set, the coefficient of determination (R(2)) and the agreement index 'd' were higher for the one that used the variable product (length x width), while the Mean Absolute Percentage Error was lower. Conclusion. The product of the simple leaf dimensions (length x width) can provide a reliable and simple non-destructive model for leaf area estimation across citrus genotypes.

Understanding the Crystallization Mechanism of a Wollastonite Base Glass Using Isoconversional, IKP Methods and Master Plots

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The role of obesity as a modifying factor in patients undergoing non-surgical periodontal therapy

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Comparative study of analytical methods by direct and first-derivative UV spectrophotometry for evaluation of losartan potassium in capsules

O losartano potássico é um agente anti-hipertensivo não peptídico, que exerce sua ação por bloqueio específico dos receptores da angiotensina II. Este trabalho propôs a validação e aplicação de métodos analíticos orientados ao controle de qualidade de losartano potássico 50 mg na forma farmacêutica cápsula, utilizando a espectrofotometria direta e derivada de primeira ordem na região do UV. Baseado nas características espectrofotométricas de losartano potássico, um sinal a 205 nm do espectro de ordem zero e um sinal a 234 nm do espectro de primeira derivada foram adequados para a quantificação. Os resultados foram usados para comparar essas duas técnicas instrumentais. O coeficiente de correlação entre as respostas e as concentrações de losartano potássico na faixa de 3,0-7,0 mg L-1 e 6,0-14,0 mg L-1 para espectrofotometria direta e derivada de primeira ordem em solução aquosa, respectivamente, foi de (r) of 0,9999 para ambos os casos. Os métodos foram aplicados para quantificação de losartano potássico em cápsulas obtidas de farmácias de manipulação locais e demonstraram ser eficientes, fáceis de aplicar e de baixo custo. Além disso, não necessitam de reagentes poluentes e requerem equipamentos economicamente viáveis.

Presence of autoantibodies against HeLa small nuclear ribonucleoproteins in chagasic and non-chagasic cardiac patients

We detected anti-human small nuclear ribonucleoprotein (snRNP) autoantibodies in chagasic patients by different immunological methods using HeLa snRNPs. ELISA with Trypanosoma cruzi total lysate antigen or HeLa human U small nuclear ribonucleoproteins (UsnRNPs) followed by incubation with sera from chronic chagasic and non-chagasic cardiac patients was used to screen and compare serum reactivity. Western blot analysis using a T. cruzi total cell extract was also performed in order to select some sera for Western blot and immunoprecipitation assays with HeLa nuclear extract. ELISA showed that 73 and 95% of chronic chagasic sera reacted with HeLa UsnRNPs and T. cruzi antigens, respectively. The Western blot assay demonstrated that non-chagasic cardiac sera reacted with high molecular weight proteins present in T. cruzi total extract, probably explaining the 31% reactivity found by ELISA. However, these sera reacted weakly with HeLa UsnRNPs, in contrast to the chagasic sera, which showed autoantibodies with human Sm (from Stefanie Smith, the first patient in whom this activity was identified) proteins (B/B', D1, D2, D3, E, F, and G UsnRNP). Immunoprecipitation reactions using HeLa nuclear extracts confirmed the reactivity of chagasic sera and human UsnRNA/RNPs, while the other sera reacted weakly only with U1snRNP. These findings agree with previously reported data, thus supporting the idea of the presence of autoimmune antibodies in chagasic patients. Interestingly, non-chagasic cardiac sera also showed reactivity with T. cruzi antigen and HeLa UsnRNPs, which suggests that individuals with heart disease of unknown etiology may develop autoimmune antibodies at any time. The detection of UsnRNP autoantibodies in chagasic patients might contribute to our understanding of how they develop upon initial T. cruzi infection.

Ultrasonic density measurement cell design and simulation of non-ideal effects

This paper presents a theoretical analysis of a density measurement cell using an unidimensional model composed by acoustic and electroacoustic transmission lines in order to simulate non-ideal effects. The model is implemented using matrix operations, and is used to design the cell considering its geometry, materials used in sensor assembly, range of liquid sample properties and signal analysis techniques. The sensor performance in non-ideal conditions is studied, considering the thicknesses of adhesive and metallization layers, and the effect of residue of liquid sample which can impregnate on the sample chamber surfaces. These layers are taken into account in the model, and their effects are compensated to reduce the error on density measurement. The results show the contribution of residue layer thickness to density error and its behavior when two signal analysis methods are used. (c) 2006 Elsevier B.V. All rights reserved.

Alternative proposal for Modal Representation of a Non-transposed Three-Phase Transmission Line with a Vertical Symmetry Plane

The objective of this paper is to show an alternative representation in time domain of a non-transposed three-phase transmission line decomposed in its exact modes by using two transformation matrices. The first matrix is Clarke's matrix that is real, frequency independent, easily represented in computational transient programs (EMTP) and separates the line into quasi-modes a, b and zero. After that, Quasi-modes a and zero are decomposed into their exact modes by using a modal transformation matrix whose elements can be synthesized in time domain through standard curve-fitting techniques. The main advantage of this alternative representation is to reduce the processing time because a frequency dependent modal transformation matrix of a three-phase line has nine elements to be represented in time domain while a modal transformation matrix of a two-phase line has only four elements. This paper shows modal decomposition process and eigenvectors of a non-transposed three-phase line with a vertical symmetry plane whose nominal voltage is 440 kV and line length is 500 km.

Effects of vitamin E supplementation on renal non-enzymatic antioxidants in young rats submitted to exhaustive exercise stress

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)