Analysis of response to enteral infusion of levodopa in patients with Parkinson's disease

Objective: We present a new evaluation of levodopa plasma concentrations and clinical effects during duodenal infusion of a levodopa/carbidopa gel (Duodopa ) in 12 patients with advanced Parkinson s disease (PD), from a study reported previously (Nyholm et al, Clin Neuropharmacol 2003; 26(3): 156-163). One objective was to investigate in what state of PD we can see the greatest benefits with infusion compared with corresponding oral treatment (Sinemet CR). Another objective was to identify fluctuating response to levodopa and correlate to variables related to disease progression. Methods: We have computed mean absolute error (MAE) and mean squared error (MSE) for the clinical rating from -3 (severe parkinsonism) to +3 (severe dyskinesia) as measures of the clinical state over the treatment periods of the study. Standard deviation (SD) of the rating was used as a measure of response fluctuations. Linear regression and visual inspection of graphs were used to estimate relationships between these measures and variables related to disease progression such as years on levodopa (YLD) or unified PD rating scale part II (UPDRS II).Results: We found that MAE for infusion had a strong linear correlation to YLD (r2=0.80) while the corresponding relation for oral treatment looked more sigmoid, particularly for the more advanced patients (YLD>18).

Estimation of genetic variance for macro- and micro-environmental sensitivity using double hierarchical generalized linear models

Background: Genetic variation for environmental sensitivity indicates that animals are genetically different in their response to environmental factors. Environmental factors are either identifiable (e.g. temperature) and called macro-environmental or unknown and called micro-environmental. The objectives of this study were to develop a statistical method to estimate genetic parameters for macro- and micro-environmental sensitivities simultaneously, to investigate bias and precision of resulting estimates of genetic parameters and to develop and evaluate use of Akaike’s information criterion using h-likelihood to select the best fitting model. Methods: We assumed that genetic variation in macro- and micro-environmental sensitivities is expressed as genetic variance in the slope of a linear reaction norm and environmental variance, respectively. A reaction norm model to estimate genetic variance for macro-environmental sensitivity was combined with a structural model for residual variance to estimate genetic variance for micro-environmental sensitivity using a double hierarchical generalized linear model in ASReml. Akaike’s information criterion was constructed as model selection criterion using approximated h-likelihood. Populations of sires with large half-sib offspring groups were simulated to investigate bias and precision of estimated genetic parameters. Results: Designs with 100 sires, each with at least 100 offspring, are required to have standard deviations of estimated variances lower than 50% of the true value. When the number of offspring increased, standard deviations of estimates across replicates decreased substantially, especially for genetic variances of macro- and micro-environmental sensitivities. Standard deviations of estimated genetic correlations across replicates were quite large (between 0.1 and 0.4), especially when sires had few offspring. Practically, no bias was observed for estimates of any of the parameters. Using Akaike’s information criterion the true genetic model was selected as the best statistical model in at least 90% of 100 replicates when the number of offspring per sire was 100. Application of the model to lactation milk yield in dairy cattle showed that genetic variance for micro- and macro-environmental sensitivities existed. Conclusion: The algorithm and model selection criterion presented here can contribute to better understand genetic control of macro- and micro-environmental sensitivities. Designs or datasets should have at least 100 sires each with 100 offspring.

Hglm: A package for fitting hierarchical generalized linear models

We present the hglm package for fitting hierarchical generalized linear models. It can be used for linear mixed models and generalized linear mixed models with random effects for a variety of links and a variety of distributions for both the outcomes and the random effects. Fixed effects can also be fitted in the dispersion part of the model.

Fitting spatial models in the R package: hglm

We present a new version of the hglm package for fittinghierarchical generalized linear models (HGLM) with spatially correlated random effects. A CAR family for conditional autoregressive random effects was implemented. Eigen decomposition of the matrix describing the spatial structure (e.g. the neighborhood matrix) was used to transform the CAR random effectsinto an independent, but heteroscedastic, gaussian random effect. A linear predictor is fitted for the random effect variance to estimate the parameters in the CAR model.This gives a computationally efficient algorithm for moderately sized problems (e.g. n<5000).

Fitting conditional and simultaneous autoregressive spatial models in hglm

We present a new version (> 2.0) of the hglm package for fitting hierarchical generalized linear models (HGLMs) with spatially correlated random effects. CAR() and SAR() families for conditional and simultaneous autoregressive random effects were implemented. Eigen decomposition of the matrix describing the spatial structure (e.g., the neighborhood matrix) was used to transform the CAR/SAR random effects into an independent, but eteroscedastic, Gaussian random effect. A linear predictor is fitted for the random effect variance to estimate the parameters in the CAR and SAR models. This gives a computationally efficient algorithm for moderately sized problems.

Primary Nesting Sites of the Piping Plover, Least Tern, Roseate Tern, and Bald Eagle

http://digitalcommons.colby.edu/atlasofmaine2006/1003/thumbnail.jpg

Auction econometrics by least squares

This paper proposes a method to structurally estimate an auction model using a variation of OLS, under commonly held assumptions in both auction theory and econometrics. In spite of its computational simplicity, the method applies to a wide variety of environments, including interdependent values in general, and certain forms of endogenous participation and bidder asymmetry. Furthermore, it can be used for hypotheses testing about the shape of the valuation distribution, valuation interdependence, or existence of bidder asymmetry.

Mecanismo LPVR - Least Present Value of Revenues como mitigador de riscos em concessões rodoviárias: uma aplicação a um caso brasileiro

Nos últimos anos o governo brasileiro tem adotado a postura de incentivo a projetos de infraestrutura, sendo as concessões rodoviárias um dos principais mecanismos. Muito se discute sobre a melhor forma de remuneração das concessionárias, sem que, ao mesmo tempo, os usuários não tenham um custo elevado e possam usufruir de bons serviçoes prestados.Essa discussão passa, principalmente, por uma análise de risco de tráfego, que hoje é inteiramente alocado as cconcessionárias. A metodologia utilizada nos últimos leilões segue uma exigência de Taxa Interna de Retorno ( TIR ) máxima, pelo Poder Concedente ( ANTT ), em termos reais e um prazo de concessão fixo. A partir de custos e investimentos estimados em determinada concessão, a ANTT define uma tarifa-teto a ser cobrada pela concessionária aos usuários através da TIR máxima exigida no projeto. Esta TIR é calculada com base no custo médio ponderado de capital ( WACC ) de empresas do setor, que tem ações negociadas na BM&F Bovespa, utilizando-se apenas dados domésticos. Neste trabalho é proposto um modelo alternativo, baseado no menor valor presente das receitas ( LPVR - Least Present Value of Revenues ). Neste modelo observamos que o risco de tráfego é bem menor para a concessionária, pois a concessão só se expira quando determinado nível de receitas exigido pela concessionária é atingido. Ou seja, para tal, é necessário um modelo de prazo flexível. Neste mecanismo, entretanto, com menor risco de tráfego, o upside e o downside, em termos de retorno, são menores em comparação com o modelo vigente. Utilizando este modelo, o Poder Concedente pode também definir um vencedor para o leilão ( a concessionária que ofertar o menor valor presente das receitas ) e também se utilizar da proposta de simulação de tráfegos para a definição de um prazo máximo para a concessão, em caso de implementação do mecanismo proposto.

Can deviation from standard beauty become appealing?: an age perspective

When exploring new perspectives on the impact of non-idealized vs. idealized body image in advertising, studies have focused mainly on body size, i.e., thin vs. heavy (Antioco et al., 2012; Smeesters & Mandel, 2006). Age remains largely unexplored, and the vast majority of ads in the market depict young models. The purpose of this research is therefore to investigate which images in advertisements – young or mature models – are more persuasive for older women (40+ years old). In this investigation, two studies were conducted. The first part was an exploratory analysis with a qualitative approach, which in turn helped to formulate the hypothesis tested in the subsequent experiment. The results of the in-depth interviews suggested a conflict over notions of imprisonment (need to follow beauty standards) and freedom (wish to deviate). The results of the experiment showed essentially that among older consumers, ads portraying older models were as persuasive as ads portraying younger models. Limitations and future research are discussed.

Mathematical analysis of maximum power generated by photovoltaic systems and fitting curves for standard test conditions

The rural electrification is characterized by geographical dispersion of the population, low consumption, high investment by consumers and high cost. Moreover, solar radiation constitutes an inexhaustible source of energy and in its conversion into electricity photovoltaic panels are used. In this study, equations were adjusted to field conditions presented by the manufacturer for current and power of small photovoltaic systems. The mathematical analysis was performed on the photovoltaic rural system I- 100 from ISOFOTON, with power 300 Wp, located at the Experimental Farm Lageado of FCA/UNESP. For the development of such equations, the circuitry of photovoltaic cells has been studied to apply iterative numerical methods for the determination of electrical parameters and possible errors in the appropriate equations in the literature to reality. Therefore, a simulation of a photovoltaic panel was proposed through mathematical equations that were adjusted according to the data of local radiation. The results have presented equations that provide real answers to the user and may assist in the design of these systems, once calculated that the maximum power limit ensures a supply of energy generated. This real sizing helps establishing the possible applications of solar energy to the rural producer and informing the real possibilities of generating electricity from the sun.

Candidíase vulvovaginal: sintomatologia, fatores de risco e colonização anal concomitante

Post-menarche patients with clinical signs of vulvovaginitis were analyzed in this study, whose aims were the following: identify the frequency of C. albicans and non C. albicans species and negative results, correlate the vaginal culture for yeast with risk factors and symptomatology; compare positive and negative results for yeast in the vaginal and anal cultures; compare the positive results for C. albicans with other results found in the vaginal and anal cultures; and compare concomitant positivity for C. albicans and non C. albicans in the vaginal and anal cultures. Sample selection occurred between May, 2003 and May, 2005, and included 99 patients from Natal, Brazil. The laboratory methods used consisted of CHROMagar Candida culture medium, thermotolerance test at 42-45°C and hypertonic NaCL, in addition to the classic methods of carbohydrate assimilation and fermentation. We used absolute numbers, percentages, means of central tendency, chi-squared test (χ2) with Yates correction, Fisher s exact test and odds ratio for statistical analysis. The most frequent species was C. albicans in 69% of the cases. The positivity for Candida spp showed an association with the use of tight-fitting intimate clothing and/or synthetics, allergic diseases and the occurrence of itching, leukorrhea and erythema. Anal colonization increased the likelihood of vaginal contamination by 2.8 and 4.9 times, respectively, for Candida spp and C. albicans. When compared to the other species, C. albicans-positive anal colonization increased by 3.7 times the likelihood of vaginal positivity. These data suggest likely vaginal contamination originating in the anus

Egg production curve fitting using nonlinear models for selected and nonselected lines of White Leghorn hens

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