João Lita da Silva

Mosquito Fauna on the Cape Verde Islands (West Africa): An Update on Species Distribution and a New Finding

ABSTRACT: To evaluate the risk of transmission of vector-borne diseases, regular updates of the geographic distribution of insect vectors are required. In the archipelago of Cape Verde, nine mosquito species have been reported. Of these, four are major vectors of diseases that have been present in the archipelago: yellow fever, lymphatic filariasis, malaria and, currently, an outbreak of dengue. In order to assess variation in mosquito biodiversity, we have carried out an update on the distribution of the mosquito species in Cape Verde, based on an enquiry of 26 unpublished technical reports (1983–2006) and on the results of an entomological survey carried out in 2007. Overall, there seems to be a general trend for an expansion of biological diversity in the islands. Mosquito species richness was negatively correlated with the distance of the islands from the mainland but not with the size of the islands. Human- and/or sporadic climatic-mediated events of dispersal may have contributed to a homogenization of species richness regardless of island size but other ecological factors may also have affected the mosquito biogeography in the archipelago. An additional species, Culex perexiguus, was collected for the first time in the archipelago during the 2007 survey.

Analysis of malaria associated genetic traits in Cabo Verde, a melting pot of European and sub Saharan settlers

Malaria has occurred in the Cabo Verde archipelago with epidemic characteristics since its colonization. Nowadays, it occurs in Santiago Island alone and though prophylaxis is not recommended by the World Health Organization, studies have highlight the prospect of malaria becoming a serious public health problem as a result of the presence of antimalarial drug resistance associated with mutations in the parasite populations and underscore the need for tighter surveillance. Despite the presumptive weak immune status of the population, severe symptoms of malaria are not observed and many people present a subclinical course of the disease. No data on the prevalence of sickle-cell trait and red cell glucose-6-phosphate dehydrogenase deficiency (two classical genetic factors associated with resistance to severe malaria) were available for the Cabo Verde archipelago and, therefore, we studied the low morbidity from malaria in relation to the particular genetic characteristics of the human host population. We also included the analysis of the pyruvate kinase deficiency associated gene, reported as putatively associated with resistance to the disease. Allelic frequencies of the polymorphisms examined are closer to European than to African populations and no malaria selection signatures were found. No association was found between the analyzed human factors and infection but one result is of high interest: a linkage disequilibrium test revealed an association of distant loci in the PKLR gene and adjacent regions, only in non-infected individuals. This could mean a more conserved gene region selected in association to protection against the infection and/or the disease.

Strong consistency of least squares estimates with i.i.d. errors with mean values not necessarily defined

We establish strong consistency of the least squares estimates in multiple regression models discarding the usual assumption of the errors having null mean value. Thus, we required them to be i.i.d. with absolute moment of order r, 01. Only moderately restrictive conditions are imposed on the model matrix. In our treatment, we use an extension of the Marcinkiewicz–Zygmund strong law to overcome the errors mean value not being defined. In this way, we get a unified treatment for the case of i.i.d. errors extending the results of some previous papers.

Advances in Regression, Survival Analysis, Extreme Values, Markov Processes and Other Statistical Applications

Part I Invited Sessions: Youden Square with Split Units (Stanislaw Franciszek Mejza and Shinji Kuriki).- Likelihood and PLS Estimators for Structural Equation Modeling: an Assessment of Sample Size, Skewness and Model Misspecification Effects (Manuel J. Vilares and Pedro S. Coelho).- Part II Communications: A Parametric Cure Model with Covariates (Ana M. Abreu and Cristina S. Rocha).- Survival Analysis Applied to the Study of Time from Diagnosis of HIV-1 Infection to AIDS in Portugal (Marta Alves, Cristina S. Rocha and Maria Teresa Paixao).- A new Independence Test for VaR Violations (P. Araujo Santos and M. I. Fraga Alves).- Discrimination Between Parametric Survival Models for Removal Times of Bird Carcasses in Scavenger Removal Trials at Wind Turbines Sites (Regina Bispo, Joana Bernardino, Tiago A. Marques and Dinis Pestana).- Uniformity (M. F. Brilhante, M. Malva, S. Mendonca, D. Pestana, F. Sequeira and S. Velosa).- Asymptotic Comparison at Optimal Levels of Minimum-Variance Reduced-Bias Tail Index Estimators (Frederico Caeiro and M. Ivette Gomes).- Extremal Behavior of the Generalized Integer-valued Random Coefficient Autoregressive Process (Luisa Canto e Castro, Dulce Gomes and Maria da Graca Temido).- Models of Individual Growth in a Random Environment: Study and Application of First Passage Times (Clara Carlos, Carlos A. Braumann and Patricia A. Filipe).- Generalized Linear Mixed Effects Model in the Analysis of Longitudinal Discrete Data (Eunice Carrasquinha, M. Helena Goncalves and M. Salome Cabral).- Risk Assessment on Campylobacter in Broiler Meat at Slaughter Level in Portugal (Marta Castel-Branco, Marilia Antunes, Patricia Inacio and Miguel Cardo).- Predicting and Treating Missing Data with Boot.EXPOS (Clara Cordeiro and M. Manuela Neves).- Bayesian Genetic Mapping of Binary Trait Loci (Cesar Correia, Nuno Sepulveda and Carlos Daniel Paulino).- Concomitant Latent Class Models Applied to Mathematics Education (Maria Eugenia Ferrao and Jose G. Dias).- Evaluating Discriminant Analysis Results (Ana Sousa Ferreira and Margarida Cardoso).- Distribution of the Number of Losses in Busy-periods of MX /G/1/n Systems (Fatima Ferreira, Antonio Pacheco and Helena Ribeiro).- Misleading Signals in Simultaneous Residual Schemes for the Process Mean and Variance of AR(1) Processes: A Stochastic Ordering Approach (Patricia Ferreira Ramos, Manuel Cabral Morais and Antonio Pacheco).- Conditional EVT for VAR Estimation: Comparison with a new Independence Test (M. I. Fraga Alves and P. Araujo Santos).- Asymptotic Distribution of the Maximum for a Chaotic Economic Model (Ana Cristina Moreira Freitas).- Adaptive Choice of Thresholds and the Bootstrap Methodology: An Empirical Study (M. Ivette Gomes, Fernanda Figueiredo and M. Manuela Neves).- Distributional Properties of Generalized Threshold ARCH Models (E. Goncalves and N. Mendes-Lopes).- Preliminary Results on Confidence Intervals for Open Bonus Malus (Gracinda R. Guerreiro, Joao T. Mexia and Maria F. Miguens).- Study of the Electrocardiographic Fluctuations on Brugada Syndrome Screening (Carla Henriques, Ana Cristina Matos and Luis Ferreira dos Santos).- Circulatory System Diseases and Neoplasms Mortality on Older Portuguese Population: A Spatio-temporal Analysis by Age and Sex (Sandra Lagarto, Carla Nunes, Dulce Gomes and Maria Filomena Mendes).- Absolute Diffusion Process: Sensitivity Measures (Manuela Larguinho, Jose Carlos Dias and Carlos A. Braumann).- Scaling Exponents in Heart Rate Variability (Argentina Leite, Maria Eduarda Silva and Ana Paula Rocha).- Prediction of Dementia Patients: A Comparative Approach Using Parametric vs. non Parametric Classifiers (Joao Maroco, Dina Silva, Manuela Guerreiro, Alexandre de Mendonca and Isabel Santana).- Pareto Scale Mixtures (Miguel Martins Felgueiras).- Fitting Johnsons SB distribution to Forest Tree Diameter (Ayana Mateus and Margarida Tome).- On a Continuous Time Stock Price Model With two Mean Reverting Regimes (Pedro P. Mota).- Generalized F Tests in Models With Random Perturbations: The Truncated Normal Case (Celia Nunes, Dario Ferreira, Sandra Ferreira and Joao T. Mexia).- Generalized Linear Models, Generalized Additive Models and Neural Networks: Comparative Study in Medical Applications (Ana Luisa Papoila, Cristina Rocha, Carlos Geraldes and Patricia Xufre).- Joint Regression Analysis and Incorporation of Environmental Variables in Stochastic Frontier Production Function: An Application to Experimental Data of Winter Rye (Dulce Gamito Pereira and Ana Sampaio).- On the Maximum and Minimum of a Stationary Random Field (Luisa Pereira).- Publication Bias and Meta-analytic Syntheses (D. Pestana, M. L. Rocha, R. Vasconcelos and S. Velosa).- Self-perception of Health Status and Socio-economic Differences in the Use of Health Services (Alexandra Pinto, Victor Lobo, Fernando Bacao and Helena Bacelar-Nicolau).- Comparison of Modal Variables Using Multivariate Analysis (Isabel Pinto Doria, Aurea Sousa, Helena Bacelar-Nicolau and Georges Le Calve).- Disentangling the Relationship Between Entrepreneurship and Job Creation by Poisson Mixture Regressions (Leandro P. Pontes and Jose G. Dias).-Simulation Study of the Calibration Technique in the Extremal Index Estimation (D. Prata Gomes, Joao T. Mexia and M. Manuela Neves).- Semi-parametric Building of the Optimal Screening Region in Supervised Classification (Sandra Ramos, Maria Antonia Amaral Turkman and Marilia Antunes).- An Application of Statistical Methods of Indirect Estimation and Projection of Internal Migration Flows Within the Portuguese Mainland (Maria FilomenaMendes, Antonio Caleiro, Sandra Lagarto and Filipe Ribeiro).- Robust Clustering Method for the Detection of Outliers: Using AIC to Select the Number of Clusters (Carla M. Santos-Pereira and Ana M. Pires).- HLA Allele and Haplotype Frequencies of the Portuguese Bone Marrow Donors Registry (Ricardo Sao Joao, Ana Luisa Papoila, Dario Ligeiro and Helder Trindade).- Independent Component Analysis for Extended Time Series in Climate Data (Fernando Sebastiao and Irene Oliveira).- Life Satisfaction: a MIMIC Approach With a Discrete Latent Variable (Patricia Serra, Jose G. Dias and Maria de Fatima Salgueiro).- An Application of MRMC ROC Curves on Radiology (Carina Silva-Fortes, Maria Antonia Amaral Turkman, Luis Lanca, Ricardo Silva and Goncalo Marques).- Some Remarks About Gibbs Variable Selection Performance (Julia Teles and Maria Antonia Amaral Turkman).- Dependence of Multivariate Extremes (C. Viseu, L. Pereira, A.P. Martins and H. Ferreira).

Integer powers of anti-tridiagonal matrices of the form antitridiagn(a, c,−a), a, c ∈ ℂ

In this paper we derive a general explicit expression for integer powers of complex anti-tridiagonal Hankel matrices having the form , using Chebyshev polynomials.In this paper we derive a general explicit expression for integer powers of complex anti-tridiagonal Hankel matrices having the form antitridiagn(a,c,−a), a,c∈C using Chebyshev polynomials.

Integer powers of anti-tridiagonal matrices of the form antitridiag n ( a , 0 , b ) , a , b ∈ R

In this paper we use Chebyshev polynomials to derive a general expression for integer powers of real anti-tridiagonal matrices with constant anti-diagonals and null northeast-to-southwest diagonal.

Saliency-based cooperative landing of a multirotor aerial vehicle on an autonomous surface vehicle

This paper presents a method for vision-based landing of a multirotor unmanned aerial vehicle (UAV) on an autonomous surface vehicle (ASV) equipped with a helipad. The method includes a mechanism for helipad behavioural search when outside the UAVs field of view, a learning saliency-based mechanism for visual tracking the helipad, and a cooperative strategy for the final vision-based landing phase. Learning how to track the helipad from above occurs during takeoff and cooperation results from having the ASV tracking the UAV for assisting its landing. A set of experimental results with both simulated and physical robots show the feasibility of the presented method.

On the characteristic polynomial, eigenvectors and determinant of heptadiagonal matrices

AbstractIn this paper, the characteristic polynomial of general heptadiagonal matrices is derived as well as eigenvectors associated to a prescribed eigenvalue. A symbolic algorithm to compute the determinant of heptadiagonal matrices is also presented allowing a suite implementation through computational software programs.Abstract In this paper, the characteristic polynomial of general heptadiagonal matrices is derived as well as eigenvectors associated to a prescribed eigenvalue. A symbolic algorithm to compute the determinant of heptadiagonal matrices is also presented allowing a suite implementation through computational software programs.

On anti-pentadiagonal persymmetric Hankel matrices with perturbed corners

In this paper we express the eigenvalues of real anti-pentadiagonal persymmetric Hankel matrices with perturbed corners as the zeros of explicit rational functions. From these prescribed eigenvalues we give an orthogonal diagonalization for these matrices and a formula to compute its integer powers. In particular, an explicit expression not depending on any unknown parameter for the determinant and the inverse of complex anti-pentadiagonal persymmetric Hankel matrices with perturbed corners is provided.

On the rates of convergence for moments convergence in regression models

In one-dimensional regression models, we establish a rate for the rth moment convergence