Evolutionary 3D Image Segmentation of Curve Epithelial Tissues of Drosophila melanogaster

Analysing biological images coming from the microscope is challenging; not only is it complex to acquire the images, but also the three-dimensional shapes found on them. Thus, using automatic approaches that could learn and embrace that variance would be highly interesting for the field. Here, we use an evolutionary algorithm to obtain the 3D cell shape of curve epithelial tissues. Our approach is based on the application of a 3D segmentation algorithm called LimeSeg, which is a segmentation software that uses a particle-based active contour method. This program needs the fine-tuning of some hyperparameters that could present a long number of combinations, with the selection of the best parametrisation being highly time-consuming. Our evolutionary algorithm automatically selects the best possible parametrisation with which it can perform an accurate and non-supervised segmentation of 3D curved epithelial tissues. This way, we combine the segmentation potential of LimeSeg and optimise the parameters selection by adding automatisation. This methodology has been applied to three datasets of confocal images from Drosophila melanogaster, where a good convergence has been observed in the evaluation of the solutions. Our experimental results confirm the proper performing of the algorithm, whose segmented images have been compared to those manually obtained for the same tissues

Spectral Bandwidth and WEC Performance Assessment

This paper investigates the dependency of wave energy conversion on the spectral bandwidth of sea-states. To this aim, the performance of an axisymmetrical Wave Energy Converter is assessed in the frequency domain by using a stochastic model in two far different wave climates (Portugal and North Sea) both represented by more than 23000 energy spectral densities obtained from measurements. The correlation between the performance and various bandwidth parameters found in the literature is observed. Then, refined methods for predicting the long-term converted wave energy based on wave statistics including spectral bandwidth are compared to more common procedures and conclusions are drawn

Unravelling the Yeast Cell Cycle Using the TriGen Algorithm

Analyzing microarray data represents a computational challenge due to the characteristics of these data. Clustering techniques are widely applied to create groups of genes that exhibit a similar behavior under the conditions tested. Biclustering emerges as an improvement of classical clustering since it relaxes the constraints for grouping allowing genes to be evaluated only under a subset of the conditions and not under all of them. However, this technique is not appropriate for the analysis of temporal microarray data in which the genes are evaluated under certain conditions at several time points. In this paper, we present the results of applying the TriGen algorithm, a genetic algorithm that finds triclusters that take into account the experimental conditions and the time points, to the yeast cell cycle problem, where the goal is to identify all genes whose expression levels are regulated by the cell cycle

Análise da variabilidade genética em acessos de mandioca resistentes a podridão mole.

A mandioca (Manihot esculenta Crantz) é uma espécie do gênero Manihot importante na culinária brasileira, principalmente no Norte e Nordeste. Como toda cultura, a mandioca também sofre com doenças e pragas em seu cultivo. No estado do Pará uma das principais doenças que acometem a cultura da mandioca é a podridão mole da raiz, causada pelos patógenos Phytophthora spp. e Fusarium spp. A busca de variabilidade genética para a resistência a essa doença é essencial para dar suporte aos programas de melhoramento da espécie. No presente trabalho, foi avaliada a ocorrência de variabilidade genética em sete acessos de mandiocas do BAG da Embrapa da Amazônia Oriental que são resistentes à podridão mole da raiz por meio de marcadores microssatélites. Foi extraído o DNA desses acessos e realizado a análise em PCR utilizando sete marcadores moleculares do tipo microssatélites (GA136, SSRY04, SSRY09, SSRY164, SSRY19, SSRY20 e SSRY21) e análise foi realizada em eletroforese capilar. Os dados foram transformados em matriz de 1 e 0 e foi utilizado o coeficiente de Jaccard para verificar a similaridade genética entre os acessos. Com estas análises, foi gerado o dendrograma pelo método UPGMA entre os acessos, bem como foram observadas as frequências alélicas e a variabilidade genética do grupo de acessos. Foi encontrada variabilidade genética entre os acessos de mandioca do BAG da Embrapa da Amazônia oriental resistentes a podridão

Chondroitin sulfate and glucosamine in the cartilage and subchondral bone repair of dogs - Histological findings

Chondroitin and glucosamine sulfate nutraceuticals are commonly used in the management of degenerative articular disease in veterinary routine. However, there are controversies on the contribution of these substances to articular cartilage. The purpose of this study was to evaluate the efficiency of a chondroitin and glucosamine sulfate-based veterinary nutraceutical on the repair of an induced osteochondral defect in a dog femoral condyle, by macroscopic, histological and histomorphometric analyses. The nutraceutical was orally administered the day following injury induction, every 24 hours (treated group, TG, n=24), compared with animals that did not receive the product (control group, CG, n=24). Six animals per group were anaesthetized for sample collection at 15, 30, 60 and 90 days after surgery. At 15 days, defects were macroscopically filled with red-pinkish tissue. After 30 days, whitish color tissue was observed, both in TG and CG animals, with firmer consistency to touch at 60 and 90 postoperative days. Histological analysis demonstrated that, in both groups, there was initial blood clot formation, which was subsequently substituted by a fibrin net, with capillary proliferation from the adjacent bone marrow and infiltration of mesenchymal cells in clot periphery. As cellular differentiation developed, repair tissue presented a fibrocartilage aspect most of the time, and new subchondral bone formation occurred in the deepest area corresponding to the defect. Histomorphometry suggested that the nutraceutical did not favor the articular cartilage repair process. It was concluded that nutraceutical did not significantly influence chondrocytes proliferation or hyaline architecture restoration.Os nutracêuticos compostos de sulfato de condroitina e glucosamina são comumente utilizados no manejo da doença articular degenerativa na rotina veterinária. Entretanto, existem controvérsias sobre a contribuição dessas substâncias à cartilagem articular. O objetivo deste trabalho foi avaliar a eficácia de um nutracêutico veterinário à base de sulfato de condroitina e glucosamina na reparação de defeitos osteocondrais induzidos no côndilo femoral de cães, através de análises macroscópica, histológica e histomorfométrica. O nutracêutico foi administrado no dia seguinte à indução da lesão, pela via oral, a cada 24 horas (grupo tratado - GT, 24 animais), sendo comparado a animais que não receberam o produto (grupo controle - GC, de igual número de animais). Aos 15, 30, 60 e 90 dias após a cirurgia, seis animais por grupo foram anestesiados para ser realizada a coleta das amostras. Aos 15 dias, os defeitos eram macroscopicamente preenchidos por tecido de coloração rósea a avermelhada. Já a partir dos 30 dias, observou-se preenchimento por tecido de coloração esbranquiçada, tanto nos animais do GT quanto nos do GC, com consistência mais firme ao toque digital aos 60 e 90 dias de pós-operatório. A análise histológica revelou que, em ambos os grupos, houve inicialmente formação de coágulo sanguíneo que, posteriormente, foi substituído por uma rede de fibrina, com proliferação de capilares a partir da medula óssea adjacente e infiltração de células mesenquimais na periferia do coágulo. À medida que se processou a diferenciação celular, o tecido de reparação se apresentou na maioria das vezes com aspecto de fibrocartilagem e, na região mais profunda da área correspondente ao defeito, ocorreu formação de osso novo subcondral. A histomorfometria sugeriu que o nutracêutico não favoreceu o processo de reparação da cartilagem articular. Concluiu-se que o nutracêutico não influenciou consideravelmente na proliferação de condrócitos nem na restauração da arquitetura hialina

Performance of processing tomatoes under different supply levels of crop evapotranspiration.

This study was installed to evaluate productive performance of two processing tomato hybrids submitted to five water depths under drip irrigation system. Five levels of crop evapotranspiration (ETc) replacement (60%, 100%, 140%, 180% and 220%) and two tomato hybrids (BRS Sena and H 9992) were tested

Persistent pusher behavior after a stroke

Pusher behavior (PB) is a postural control disorder characterized by actively pushing away from the nonparetic side and resisting passive correction with a tendency to fall toward the paralyzed side.1 These patients have no awareness that their active pushing is counterproductive, which precludes the patients from standing without assistance. Several studies have already demonstrated that PB can occur in patients with lesions in both hemispheres, and PB is distinct from neglect and anosognosia.2-8 The high frequency of the association between PB and neurophysiological deficits might reflect an increased vulnerability of certain regions to stroke-induced injury rather than any direct involvement with the occurrence of PB.9,10 Traditionally, PB has only been reported in stroke patients; however, it has also been described under nonstroke conditions.8 Previous imaging studies have suggested the posterolateral thalamus as the brain structure that is typically damaged in pusher patients.4,11 Nevertheless, other cortical and subcortical areas, such as the insular cortex and post-central gyrus, have also been highlighted as structures that are potentially involved in the pathophysiology of PB.2,12-1

Climatology of easterly wave disturbances over the tropical South Atlantic

A 21-yr climatology of Easterly Waves Disturbances (EWDs) over the Tropical South Atlantic (TSA) has been examined using data from the European Centers for Medium-Range Weather Forecasting (ECMWF) interim reanalysis (ERAI) and satellite data. This includes the frequency distribution of EWDs and their interannual variability. The large-scale environment associated with EWDs has been investigated for the coastal region of Northeast Brazil (NEB) for the rainy (April-August) season using a composite analysis. To better understand the life cycle of EWDs, an automated tracking scheme has been used to track vorticity centers associated with the EWDs in the ERAI data. EWDs were first identified in ERAI, resulting in 518 observed cases. These were found to show notable interannual variability with around 16-40 episodes by year and with average lifetime of 4-6 days. Of the identified EWDs, 97% reached the coast of NEB, of which 64% were convective in nature and 14% moved across the NEB region and reached the Amazon. The annual occurrence of EWDs seems to be lower (higher) during El Niño (La Niña). The monthly occurrence of EWDs shows higher activity in the rainy season. EWDs originate in association with five types of system: cold fronts, convective clusters from the west coast of Africa, Intertropical Convergence Zone and Tropical Upper Tropospheric Cyclonic Vortices. The composite analysis presents strong relative vorticity (RV) and divergence anomalies at low levels, as well as in the vertical profiles of relative humidity and vertical velocity (omega). The precipitation composites show that the EWDs propagate between the TSA and NEB and contribute at least 60% of the total rainfall over the east coast of NEB throughout the rainy season