Design-based random permutation models with auxiliary information

We extend the random permutation model to obtain the best linear unbiased estimator of a finite population mean accounting for auxiliary variables under simple random sampling without replacement (SRS) or stratified SRS. The proposed method provides a systematic design-based justification for well-known results involving common estimators derived under minimal assumptions that do not require specification of a functional relationship between the response and the auxiliary variables.

An extension of the invariance principle for dwell-time switched nonlinear systems

In this paper, we propose an extension of the invariance principle for nonlinear switched systems under dwell-time switched solutions. This extension allows the derivative of an auxiliary function V, also called a Lyapunov-like function, along the solutions of the switched system to be positive on some sets. The results of this paper are useful to estimate attractors of nonlinear switched systems and corresponding basins of attraction. Uniform estimates of attractors and basin of attractions with respect to time-invariant uncertain parameters are also obtained. Results for a common Lyapunov-like function and multiple Lyapunov-like functions are given. Illustrative examples show the potential of the theoretical results in providing information on the asymptotic behavior of nonlinear dynamical switched systems. (C) 2012 Elsevier B.V. All rights reserved.

Morphological records of oocyte maturation in the parthenogenetic tick Amblyomma rotundatum Koch, 1844 (Acari: Ixodidae)

Oocyte maturation in the thelytokous parthenogenetic tick Amblyomma rotundatum was examined for the first time using light and scanning electron microscopy. The panoistic ovary lacks nurse and follicular cells and is a single continuous tubular structure forming a lumen delimited by the ovarian wall. Oocytes of tick species are usually classified according to cytoplasm appearance, the presence of germinal vesicle, the presence of yolk granules, and the chorion. However, for this species, we also use oocyte size as an auxiliary tool since most oocytes were in stages I-Ill and were histologically very similar. Oocytes were classified into five development stages, and specific characteristics were observed: mature oocytes with thin chorion, pedicel cells arranged forming an epithelium with two Or more oocytes attached by the same structure, and a large number of oocytes in the process of reabsorption. (C) 2011 Elsevier GmbH. All rights reserved.

Molecular detection of Streptococcus agalactiae in bovine raw milk samples obtained directly from bulk tanks

Mastitis is the most common infectious disease affecting dairy cattle; in addition, it remains the most economically important disease of dairy industries around the world. Streptococcus agalactiae, a contagious pathogen associated with subclinical mastitis, is highly infectious. This bacterium can cause an increase in bulk tank bacterial counts (BTBC) and bulk tank somatic cell counts (BTSCC). The microbiological identification of S. agalactiae in samples from bulk tanks is an auxiliary method to control contagious mastitis. Thus, there are some limitations for time-consuming cultures or identification methods and additional concerns about the conservation and transport of samples. Bulk tank samples from 247 dairy farms were cultured and compared through polymerase chain reaction (PCR), directed to 16S rRNA genes of S. agalactiae, followed by BTBC and S. agalactiae isolation. The mean value of BTBC was 1.08 x 10(6) CFU mL(-1) and the bacterium was identified through the microbiological method in 98 (39.7%; CI95% = 33.8-45.9%) and through PCR in 110 (44.5%; CI95% = 38.5-50.8%) samples. Results indicated sensitivity of 0.8571 +/- 0.0353 (CI95% = 0.7719-0.9196) and specificity of 0.8255 +/- 0.0311 (CI95% = 0.7549-0.8827). The lack of significant difference between microbiological and molecular results (kappa = 0.6686 +/- 0.0477 and CI95% = 0.5752-0.7620) indicated substantial agreement between the methods. This suggests that PCR can be used for bulk tank samples to detect contagious mastitis caused by S. agalactiae. (C) 2011 Elsevier Ltd. All rights reserved.

Effect of Chlorhexidine on Denture Biofilm Accumulation

Purpose: Adequate denture hygiene can prevent and treat infection in edentulous patients, who are frequently elderly and have difficulty brushing their teeth. This study evaluated the efficacy of complete denture biofilm removal using a chlorhexidine solution in two concentrations: 0.12% and 2.0%. Materials and Methods: Sixty complete denture wearers participated in a trial for 21 days after receiving brushing instructions. They were distributed into three groups, according to the tested solution and regimen (n = 20): (G1) Control (daily overnight soaking in water); (G2) daily immersion at home in 0.12% chlorhexidine for 20 minutes after dinner; and (G3) a single immersion in 2.0% chlorhexidine for 5 minutes at the end of the experimental period, performed by a professional. Biofilm coverage area (%) was quantified on the internal surface of maxillary dentures at baseline and after 21 days. Afterward, the differences between initial and posttreatment results were compared by means of the Kruskal-Wallis test (a = 0.05). Results: Median values for biofilm coverage area after treatment were: (G1) 36.0%; (G2) 5.3%; and (G3) 1.4%. Differences were significant (KW = 35.25; p < 0.001), although G2 and G3 presented similar efficacy in terms of biofilm removal. Conclusions: Both chlorhexidine-based treatments had a similar ability to remove denture biofilm. Immersion in 0.12% or 2.0% chlorhexidine solutions can be used as an auxiliary method for cleaning complete dentures.

Optical parametric oscillation with distributed feedback in cold atoms

There is currently a strong interest in mirrorless lasing systems(1), in which the electromagnetic feedback is provided either by disorder (multiple scattering in the gain medium) or by order (multiple Bragg reflection). These mechanisms correspond, respectively, to random lasers(2) and photonic crystal lasers(3). The crossover regime between order and disorder, or correlated disorder, has also been investigated with some success(4-6). Here, we report one-dimensional photonic-crystal lasing (that is, distributed feedback lasing(7,8)) with a cold atom cloud that simultaneously provides both gain and feedback. The atoms are trapped in a one-dimensional lattice, producing a density modulation that creates a strong Bragg reflection with a small angle of incidence. Pumping the atoms with auxiliary beams induces four-wave mixing, which provides parametric gain. The combination of both ingredients generates a mirrorless parametric oscillation with a conical output emission, the apex angle of which is tunable with the lattice periodicity.

Genome wide scan for quantitative trait loci affecting tick resistance in cattle (Bos taurus × Bos indicus)

Abstract Background In tropical countries, losses caused by bovine tick Rhipicephalus (Boophilus) microplus infestation have a tremendous economic impact on cattle production systems. Genetic variation between Bos taurus and Bos indicus to tick resistance and molecular biology tools might allow for the identification of molecular markers linked to resistance traits that could be used as an auxiliary tool in selection programs. The objective of this work was to identify QTL associated with tick resistance/susceptibility in a bovine F2 population derived from the Gyr (Bos indicus) × Holstein (Bos taurus) cross. Results Through a whole genome scan with microsatellite markers, we were able to map six genomic regions associated with bovine tick resistance. For most QTL, we have found that depending on the tick evaluation season (dry and rainy) different sets of genes could be involved in the resistance mechanism. We identified dry season specific QTL on BTA 2 and 10, rainy season specific QTL on BTA 5, 11 and 27. We also found a highly significant genome wide QTL for both dry and rainy seasons in the central region of BTA 23. Conclusions The experimental F2 population derived from Gyr × Holstein cross successfully allowed the identification of six highly significant QTL associated with tick resistance in cattle. QTL located on BTA 23 might be related with the bovine histocompatibility complex. Further investigation of these QTL will help to isolate candidate genes involved with tick resistance in cattle.

Idade no diagnóstico e no início da intervenção de crianças deficientes auditivas em um serviço público de saúde auditiva brasileiro

INTRODUÇÃO: Quanto mais precoce o diagnóstico e intervenção da deficiência auditiva, menor será o impacto para o desenvolvimento das habilidades cognitivas, auditivas e de linguagem da criança. OBJETIVO: Caracterizar a idade no diagnóstico e no início da intervenção da perda auditiva e o acompanhamento de crianças atendidas em um serviço público de saúde auditiva brasileiro - Espaço Reouvir do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. MÉTODO: Estudo retrospectivo com informações de 166 prontuários de crianças no que se refere a: gênero; etiologia, tipo, grau e lateralidade da deficiência auditiva; idade do diagnóstico e da adaptação do Aparelho de Amplificação Sonora Individual (AASI) e acompanhamento no serviço. RESULTADOS: A amostra foi composta por 56% homens e 44% mulheres. A etiologia predominante foi a de origem multifatorial. A perda auditiva do tipo neurossensorial ocorreu em 88,6% dos casos. O grau de perda auditiva moderado foi o de maior ocorrência (30,7%), simetria entre as orelhas foi encontrada em 69,9% dos casos e perda auditiva unilateral em 2,4%. A idade média no diagnóstico foi de 5,46 anos e na intervenção de 6,86 anos. Um total de 96,98% das crianças já havia completado o processo de adaptação e 78,32% permaneciam em acompanhamento. CONCLUSÃO: O Programa Reouvir - HCFMUSP ainda recebe crianças, seja para o diagnóstico e/ou para a intervenção, de maneira tardia. Entretanto, ainda assim faz-se possível à realização do acompanhamento de um número significativo de crianças usuárias de AASI, possibilitando um processo de adaptação mais efetivo.

Estimulabilidade: medida auxiliar na identificação de dificuldade na produção dos sons

OBJETIVO: Analisar a efetividade da estimulabilidade como prova complementar ao diagnóstico do transtorno fonológico (TF) e descrever o desempenho de crianças com ausência de sons no inventário fonético quanto a sons ausentes estimuláveis, gravidade, gênero, idade e ocorrência de diferentes processos fonológicos. MÉTODOS: Participaram 130 crianças de ambos os gêneros, entre 5 anos e 10 anos e 10 meses de idade, distribuídas em dois grupos: Grupo Pesquisa (GP), composto por 55 crianças com TF; e Grupo Controle (GC), composto por 75 crianças sem alterações fonoaudiológicas. A partir da aplicação da prova de Fonologia, foi calculada a gravidade do TF por meio do Percentual de Consoantes Corretas-Revisada (PCC-R) e verificado o inventário fonético. Para cada som ausente do inventário foi aplicada a estimulabilidade em imitação de palavras. O GP foi dividido em GP1 (27 crianças que apresentaram sons ausentes) e GP2 (28 crianças com inventário completo). RESULTADOS: Nenhuma criança do GC apresentou som ausente no inventário e no GP1 49% apresentaram sons ausentes. Houve ausência da maioria dos sons da língua. As médias do PCC-R foram menores no GP1, indicando maior gravidade. No GP1, 22 crianças foram estimuláveis e cinco não o foram a qualquer som. Houve associação entre os processos fonológicos mais ocorrentes no TF e a necessidade de avaliação da estimulabilidade, o que indica que a dificuldade em produzir os sons ausentes reflete dificuldade de representação fonológica. A estimulabilidade sofre influência da idade, mas não do gênero. CONCLUSÃO: A prova de estimulabilidade é efetiva para identificar dentre crianças com sons ausentes do inventário, aquelas que são estimuláveis. Tais crianças com TF, que apresentam sons ausentes do inventário, são mais graves uma vez que os valores do PCC-R são mais baixos. As crianças com sons ausentes são estimuláveis em sua maioria, e podem não ser estimuláveis para sons com estrutura silábica ou gesto articulatório complexos. A dificuldade em produzir os sons ausentes reflete dificuldade de representação fonológica. A produção motora da fala demonstrou receber influência da maturação de forma semelhante entre meninos e meninas.

Brain activity and medical diagnosis: an EEG study

Abstract Background Despite new brain imaging techniques that have improved the study of the underlying processes of human decision-making, to the best of our knowledge, there have been very few studies that have attempted to investigate brain activity during medical diagnostic processing. We investigated brain electroencephalography (EEG) activity associated with diagnostic decision-making in the realm of veterinary medicine using X-rays as a fundamental auxiliary test. EEG signals were analysed using Principal Components (PCA) and Logistic Regression Analysis Results The principal component analysis revealed three patterns that accounted for 85% of the total variance in the EEG activity recorded while veterinary doctors read a clinical history, examined an X-ray image pertinent to a medical case, and selected among alternative diagnostic hypotheses. Two of these patterns are proposed to be associated with visual processing and the executive control of the task. The other two patterns are proposed to be related to the reasoning process that occurs during diagnostic decision-making. Conclusions PCA analysis was successful in disclosing the different patterns of brain activity associated with hypothesis triggering and handling (pattern P1); identification uncertainty and prevalence assessment (pattern P3), and hypothesis plausibility calculation (pattern P2); Logistic regression analysis was successful in disclosing the brain activity associated with clinical reasoning success, and together with regression analysis showed that clinical practice reorganizes the neural circuits supporting clinical reasoning.