Computation of the inverse Laplace Transform based on a Collocation method which uses only real values

We develop a numerical algorithm for inverting a Laplace transform (LT), based on Laguerre polynomial series expansion of the inverse function under the assumption that the LT is known on the real axis only. The method belongs to the class of Collocation methods (C-methods), and is applicable when the LT function is regular at infinity. Difficulties associated with these problems are due to their intrinsic ill-posedness. The main contribution of this paper is to provide computable estimates of truncation, discretization, conditioning and roundoff errors introduced by numerical computations. Moreover, we introduce the pseudoaccuracy which will be used by the numerical algorithm in order to provide uniform scaled accuracy of the computed approximation for any x with respect to ex . These estimates are then employed to dynamically truncate the series expansion. In other words, the number of the terms of the series acts like the regularization parameter which provides the trade-off between errors. With the aim to validate the reliability and usability of the algorithm experiments were carried out on several test functions

Culture-dependent and sequencing methods revealed the absence of a bacterial community residing in the urine of healthy cats

A growing number of studies suggest that the lower urinary tract of humans and dogs can harbor a urinary microbiota. Nevertheless, a certain concern has developed that the microbiota reported could be due to unaccounted contamination, especially in low-biomass samples. The aim of this study was to investigate the bacterial community which populates the urine of healthy cats using two approaches: a culture-dependent approach which consisted of the expanded quantitative urine culture (EQUC) techniques capable of identifying live bacteria not growing in standard urine cultures, and a culture-independent approach which consisted of 16S ribosomal RNA next generation sequencing (16S rRNA NGS) capable of identifying bacterial DNA and exploring microbial diversity with high resolution. To avoid confounding factors of possible bacterial contamination, the urine was sampled using ultrasound-guided cystocentesis, and several sample controls and negative controls were analyzed. The urine sampled from the 10 cats included in the study showed no bacterial growth in the EQUC procedure. Although several reads were successfully originated using 16S rRNA NGS, a comparable pattern was observed between urine samples and the negative control, and no taxa were statistically accepted as non-contaminant. Taken together, the results obtained allowed stating that no viable bacteria were present in the urine of healthy cats without lower urinary tract disease and urinary tract infections, and that the bacterial DNA detected was of contaminant origin

Comparing computer-generated and pathologist-generated tumour segmentations for immunohistochemical scoring of breast tissue microarrays

BACKGROUND: Tissue microarrays (TMAs) have become a valuable resource for biomarker expression in translational research. Immunohistochemical (IHC) assessment of TMAs is the principal method for analysing large numbers of patient samples, but manual IHC assessment of TMAs remains a challenging and laborious task. With advances in image analysis, computer-generated analyses of TMAs have the potential to lessen the burden of expert pathologist review. METHODS: In current commercial software computerised oestrogen receptor (ER) scoring relies on tumour localisation in the form of hand-drawn annotations. In this study, tumour localisation for ER scoring was evaluated comparing computer-generated segmentation masks with those of two specialist breast pathologists. Automatically and manually obtained segmentation masks were used to obtain IHC scores for thirty-two ER-stained invasive breast cancer TMA samples using FDA-approved IHC scoring software. RESULTS: Although pixel-level comparisons showed lower agreement between automated and manual segmentation masks (κ=0.81) than between pathologists' masks (κ=0.91), this had little impact on computed IHC scores (Allred; [Image: see text]=0.91, Quickscore; [Image: see text]=0.92). CONCLUSIONS: The proposed automated system provides consistent measurements thus ensuring standardisation, and shows promise for increasing IHC analysis of nuclear staining in TMAs from large clinical trials

Genetic dissimilarity in conyza sumatrensis revealed by simple sequence repeat (SSR) markers.

In view of the rapid evolution of Conyza sumatrensis populations resistant to glyphosate, it is necessary to understand the genetic diversity aimed to improve strategies for managing this weed. We investigated the genetic dissimilarity among 15 biotypes of C. sumatrensis from different geographic regions using microsatellite loci. The biotypes, were cultivated in a greenhouse to obtain vegetal material for DNA extraction. Nineteen microsatellite markers (SSR), were developed for C. sumatrensis biotypes. The genetic dissimilarity was estimated by the Jaccard coefficient (JC) and the biotypes grouped by the UPGMA method. The results demonstrated a high dissimilarity (JC = 7.14 to 82.62) of the analyzed material, with the biotypes forming five groups, being one group formed just by the susceptible biotype and in the others grouped by biotypes from distinct locations in the same group The high genetic diversity of C. sumatrensis indicates that the biotypes may show different responses to different management strategies, and that the mechanisms of resistance to herbicides and characteristics of evolution of populations due to adaptability may be some of the factors involved in the genetic variability of the species. Keywords: polymorphism; SSR; tall fleabane; genetic variability RESUMO: Tendo em vista a rápida evolução das populações de Conyza sumatrensis resistentes ao glifosato, é necessário entender a diversidade genética com vistas a melhorar as estratégias de manejo dessa planta daninha. Diante do exposto, objetivou-se com este trabalho investigar a dissimilaridade genética entre 15 biótipos de C. sumatrensis de diferentes regiões geográficas usando marcadores moleculares microssatélites. Os biótipos foram cultivados em casa de vegetação, para obtenção de material vegetal para extração de DNA. Dezenove marcadores microssatélites (SSR) foram desenvolvidos para os biótipos de C. sumatrensis. A dissimilaridade genética foi estimada pelo coeficiente de Jaccard (JC), e os biótipos, agrupados pelo método UPGMA. Os resultados demonstraram alta dissimilaridade (JC = 7,14 a 82,62) do material analisado, com os biótipos formando cinco grupos. A alta diversidade genética de C. sumatrensis indica que os biótipos podem apresentar distintas respostas a diferentes estratégias de manejo e que os mecanismos de resistência a herbicidas podem ser um dos fatores envolvidos na variabilidade genética das espécies. Palavras-chave: polimorfismo; SSR; buva; variabilidade genétic

Topcrosses in the selection of testers and inbred lines S3 for the yield and bromatological quality of silage maize.

The study aiming to evaluate the combining ability of maize partially inbred lines (S3) in crosses with testers ofnarrow genetic base aiming at the selection of the inbred lines, testers and topcross hybrids. Three simple latticetrials with 81 treatments were carried out in the 2014/2015 and 2015/2016 growing seasons. For each growingseason, trials were used to evaluate the topcross hybrids obtained in combination with the testers AG8088,DKB330 (single-cross hybrids) and 9.H33.3 (line). The hybrid AG8088 and line 9.H3.33 were the best testers forgrain yield. The line 9.H3.33 was the best tester for the traits related to yield and quality of silage maize. Theinbred lines that stood out for their combining abilities and capacity of generating great topcross hybrids with thetesters (i.e., 201-23.2, 201-59.1, 201-80.2, 201-81.5, 203-195.3, 201-100.4, 201-145.4, 201-169.3, 202-155, 202-159, 203-23, 203- 31, 203-32, 203-38, 203-75, 203-98, 203-111, 203-135, 203-139, 203-150, 203-188, 203-235,and 203-237) should be maintained in the UEM silage maize breeding program. Progenies 201-59.01, 201-100.4,203-135, 203-150, 203-235 and 203-254 were selected as tester lines of progenies derived from selfing of thetesters AG8088 and DKB330 to improve the silage maize quality. The topcross hybrids 201-95.3 x 9.H3.33, 203-71x 9.H3.33, 203-72 x 9.H3.33, 203-88 x 9.H3.33, 203-139 x 9.H3.33, and 203-150 x 9.H3.33 were selected for goodperformance for agronomic and bromatological silage maize traits. These hybrids are indicated for evaluationsin more environments, with a view to recommending commercial cultivars for grain and silage production in thefuture

Biologia molecular aplicada à ciência das plantas daninhas.

The weeds have high genetic variability, mainly for this, they are adapted to environments disturbed by humans. Although weed control has evolved positively in recent years, they continue to interfere with agricultural production. The objective of this bibliographic review is to present the contribution of molecular biology in the studies applied to herbology. There area gap in what we learn about weed genomics, which could help us manage and improve the competitiveness of weed crops. Many studies in the field of weed science can be carried out using molecular biology techniques. The characterization of the genome of weed species, aiming to identify species with higher accuracy, identification of herbicide resistant species and its mechanism of resistance, genetic variability and similarity among weed populations, identification of genes involved in the interaction processes between plants, among other.As plantas daninhas possuem elevada variabilidade genética, e principalmente por este motivo, são adaptadas a ambientes com intensa atividade humana. Embora o controle de plantas daninhas tenha evoluído de maneira positiva nos últimos anos, elas continuam a interferir na produção agrícola. O objetivo desta revisão bibliográfica é apresentar a contribuição da biologia molecular nos estudos aplicados a herbologia. Há lacunas entre o que aprendemos sobre genômica de plantas daninhas e como esses conhecimentos poderiam nos auxiliar no manejo e melhorar a competividade de culturas agrícolas frente às plantas daninhas. Muitos estudos na área da ciência das plantas daninhas podem ser realizados com o emprego de técnicas de biologia molecular, sendo eles: caracterização do genoma de espécies de plantas daninhas, visando à identificação destes com maior acurácia, identificação de espécies resistentes a herbicidas e seu mecanismo de resistência, variabilidade e similaridade genética entre populações de plantas daninhas, identificação de genes envolvidos nos processos de interação entre plantas, dentre outros