86 research outputs found
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Morphological Estimation of Cellularity on Neo-Adjuvant Treated Breast Cancer Histological Images
This paper describes a methodology that extracts key morphological features from histological breast cancer images in order to automatically assess Tumour Cellularity (TC) in Neo-Adjuvant treatment (NAT) patients. The response to NAT gives information on therapy efficacy and it is measured by the residual cancer burden index, which is composed of two metrics: TC and the assessment of lymph nodes. The data consist of whole slide images (WSIs) of breast tissue stained with Hematoxylin and Eosin (H&E) released in the 2019 SPIE Breast Challenge. The methodology proposed is based on traditional computer vision methods (K-means, watershed segmentation, Otsuâs binarisation, and morphological operations), implementing colour separation, segmentation, and feature extraction. Correlation between morphological features and the residual TC after a NAT treatment was examined. Linear regression and statistical methods were used and twenty-two key morphological parameters from the nuclei, epithelial region, and the full image were extracted. Subsequently, an automated TC assessment that was based on Machine Learning (ML) algorithms was implemented and trained with only selected key parameters. The methodology was validated with the score assigned by two pathologists through the intra-class correlation coefficient (ICC). The selection of key morphological parameters improved the results reported over other ML methodologies and it was very close to deep learning methodologies. These results are encouraging, as a traditionally-trained ML algorithm can be useful when limited training data are available preventing the use of deep learning approaches
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Estimation of cellularity in tumours treated with Neoadjuvant therapy: A comparison of Machine Learning algorithms
This paper describes a method for residual tumour cellularity (TC) estimation in Neoadjuvant treatment (NAT) of advanced breast cancer. This is determined manually by visual inspection by a radiologist, then an automated computation will contribute to reduce time workload and increase precision and accuracy. TC is estimated as the ratio of tumour area by total image area estimated after the NAT. The method proposed computes TC by using machine learning techniques trained with information on morphological parameters of segmented nuclei in order to classify regions of the image as tumour or normal. The data is provided by the 2019 SPIE Breast challenge, which was proposed to develop automated TC computation algorithms. Three algorithms were implemented: Support Vector Machines, Nearest K-means and Adaptive Boosting (AdaBoost) decision trees. Performance based on accuracy is compared and evaluated and the best result was obtained with Support Vector Machines. Results obtained by the methods implemented were submitted during ongoing challenge with a maximum of 0.76 of prediction probability of success
Impact of environmental and genetic factors on the scale shape of zebrafish, Danio rerio (Hamilton 1822): A geometric morphometric study
Intraspecific morphological variability may reflect either genetic divergence among groups of individuals or response of individuals to environmental circumstances within the frame of phenotypic plasticity. Several studies were able to discriminate wild fish populations based on their scale shape. Here we examine whether the variations in the scale shape in fish populations could be related to genetic or environmental factors, or to both of them. In the first experiment, two inbred lines of zebrafish Danio rerio (Hamilton 1822) reared under identical environmental conditions were compared. Secondly, to find out what effect environmental factors might have, offsprings were divided into two groups and reared on different diets for 12 weeks. Potential recovery of scales from an environmental effect was also assessed. Experimental groups could successfully be distinguished according to the shape of scales in both experiments, and the results showed that both genetic and environmental factors may notably influence scale shape. It was concluded that scale shape analysis might be used as an explanatory tool to detect potential variability of environmental influences impacting genetically homogeneous groups of fish. However, due to its sensitivity to environmental heterogeneity, the applicability of this technique in identifying intraspecific stock membership of fish could be limited
A pharmaco-economic analysis of second-line treatment with imatinib or sunitinib in patients with advanced gastrointestinal stromal tumours
Second-line treatments recommended by the National Cancer Center Network to manage advanced-stage gastrointestinal stromal tumours (GIST) were evaluated to determine the cost and cost-effectiveness of each intervention in the Mexican insurance system, the Instituto Mexicano del Seguro Social (IMSS). Treatments examined over a 5-year temporal horizon to estimate long-term costs included 800âmgâdayâ1 of imatinib mesylate, 50âmgâdayâ1 of sunitinib malate (administered in a 4 week on/2 week rest schedule), and palliative care. The mean cost (MC), cost-effectiveness, and benefit of each intervention were compared to determine the best GIST treatment from the institutional perspective of the IMSS. As sunitinib was not reimbursed at the time of the study, a Markov model and sensitivity analysis were conducted to predict the MC and likelihood of reimbursement. Patients taking 800âmgâdayâ1 of imatinib had the highest MC (±s.d.) of treatment at 17â805.87 USD (±694.83 USD); and palliative care had the least MC over treatment duration as the cost was $2071.86 USD (±472.88 USD). In comparison to palliative care, sunitinib is cost-effective for 38.9% of patients; however, sunitinib delivered the greatest survival benefit as 5.64 progression-free months (PFM) and 1.4 life-years gained (LYG) were obtained in the economic model. Conversely, patients on imatinib and palliative care saw a lower PFM of 5.28 months and 2.58 months and also fewer LYG (only 1.31 and 1.08 years, respectively). Therefore, economic modeling predicts that reimbursing sunitinib over high dose imatinib in the second-line GIST indication would deliver cost savings to the IMSS and greater survival benefits to patients
Recognising Victimhood: Lessons from the International Criminal Court and Mass Claim Programmes for the Compensation Procedure Parallel to the Trial of International Crimes in the Netherlands
In the Netherlands, the Dutch criminal court in The Hague (hereinafter: âNetherlands International Crimes Courtâ or âNIC courtâ) is assigned to try international crimes, and to provide compensation to victims of such crimes. Whereas it has specific criminal laws at its disposal to try international crimes, it applies âregularâ Dutch civil law to assess claims for compensation. Yet compensation for international crimes entails challenges that are quite different from domestic crimes: international crimes are normally committed against a large number of victims, and frequently result in bodily harm. This article argues that the NIC court will most likely rule a large number of claims for compensation inadmissible, as a consequence of which victims cannot benefit from the advantages inherent in the award of compensation within the criminal process. It then explores the adjudicative and reparatory standards that the International Criminal Court and mass claim programmes have applied to simplify both the adjudication of a large number of claims, and the calculation of a large number of instances of bodily damage. It is submitted that adoption by the NIC court of international reparatory standards could facilitate the assessment of a large number of civil claims within the criminal process, without prejudice to the legitimate interests of the defendant for an adequate procedure. However, these standards require the NIC court to strike a new balance between tailor-made compensation and symbolic compensation, and thereby between corrective justice and restorative justice
Population genomics applications for conservation: the case of the tropical dry forest dweller Peromyscus melanophrys
Recent advances in genomic sequencing have opened new horizons in the study of population genetics and evolution in non-model organisms. However, very few population genomic studies have been performed on wild mammals to understand how the landscape affects the genetic structure of populations, useful information for the conservation of biodiversity. Here, we applied a genomic approach to evaluate the relationship between habitat features and genetic patterns at spatial and temporal scales in an endangered ecosystem, the Tropical Dry Forest (TDF). We studied populations of the Plateau deer mouse Peromyscus melanophrys to analyse its genomic diversity and structure in a TDF protected area in the Huautla Mountain Range (HMR), Mexico based on 8,209 SNPs obtained through Genotyping-by-Sequencing. At a spatial scale, we found a significant signature of isolation-by-distance, few significant differences in genetic diversity indices among study sites, and no significant differences between habitats with different levels of human perturbation. At a temporal scale, while genetic diversity levels fluctuated significantly over time, neither seasonality nor disturbance levels had a significant effect. Also, outlier analysis revealed loci potentially under selection. Our results suggest that the population genetics of P. melanophrys may be little impacted by anthropogenic disturbances, or by natural spatial and temporal habitat heterogeneity in our study area. The genome-wide approach adopted here provides data of value for conservation planning, and a baseline to be used as a reference for future studies on the effects of habitat fragmentation and seasonality in the HMR and in TDF
Structure and Optical Properties of Doped SiO2 Mesoporous Glasses
Monolithic mesoporous silica glasses were synthesized. The presence of Cu2+ and Fe3+ cations during the synthesis of sol-gel precursors leads to different morphologies and pore sizes. The materials are characterized via IR and Raman scattering spectra to detect surface groups and -Si-O-Si- rings (i.e., 3â6 Si atoms) and morphology is examined through electron microscopy. N2 sorption isotherms reveal details of the mesoporous structure of the materials, which are endowed with significantly large surface areas and pore volumes. Vapor percolation occurs in these samples because of a void arrangement consisting of pore bulges delimited by narrower necks. The optical characterization shows the luminescence spectrum and thermoluminescent behavior subjected to successive exposures of beta particles
CaracterizaciĂłn de hematomas en canales de bovinos de carne en MĂ©xico. [abstract].
Los hematomas ocurren debido a golpes o contusiones que provocan la rotura de vasos sanguĂneos, con la consecuente acumulaciĂłn de sangre en los tejidos en distintas regiones anatĂłmicas de las canales bovinas, con diversa extensiĂłn y profundidad
Optimum timing for assessing phenotypic resistance against gastrointestinal nematodes in Pelibuey ewes
The objective was to identify the optimal stage of production to evaluate the resistance of Pelibuey ewes against gastrointestinal nematodes (GIN). Faecal egg count (FEC) was used to classify the ewes as resistant, sensible or intermediate against GIN. Forty-seven ewes were mating during 30 d. The gestation was verified by ultrasonography, and the breeding date was used to calculate the productive stages. Faeces were taken weekly to determine the FEC. Blood samples were taken to determine the packed cell volume (PCV), the peripheral eosinophils count (PEC), plasma protein concentration (PP), and Immunoglobulin A (IgA) against Haemonchus contortus. The body condition score (BCS) was recorded at each visit. Six moments during the study (early, mid and late gestation; early, mid and late lactation) were considered. The ewes were classified according to FEC (mean FEC ± three standard errors). The higher FEC occurred during all lactation stages than during early and mid-gestation stages (P<0.05). PCV, PP, and BCS during early gestation stage were higher than shown during the lactation stages (P<0.01). The PEC and IgA were higher during all lactation stages than early and mid-gestation stages (P<0.05). Concerning the type of birth, double births showed higher FEC than single birth (P<0.01). The highest values of accuracy (100 %) and concordance (Youden's J = 1.0) were found during early lactation. Therefore, it is concluded that the optimal stage of production to evaluate phenotypic resistance against GIN infections in Pelibuey ewes was during the early lactation
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