BACH: Grand challenge on breast cancer histology images

Aresta, Guilherme,Araú,jo, Teresa,Kwok, Scotty,Chennamsetty, Sai Saketh,Safwan, Mohammed,Alex, Varghese,Marami, Bahram,Prastawa, Marcel,Chan, Monica,Donovan, Michael,Fernandez, Gerardo,Zeineh, J Elsevier 2019 Medical image analysis Vol.56 No.-

<P><B>Abstract</B></P> <P>Breast cancer is the most common invasive cancer in women, affecting more than 10% of women worldwide. Microscopic analysis of a biopsy remains one of the most important methods to diagnose the type of breast cancer. This requires specialized analysis by pathologists, in a task that i) is highly time- and cost-consuming and ii) often leads to nonconsensual results. The relevance and potential of automatic classification algorithms using hematoxylin-eosin stained histopathological images has already been demonstrated, but the reported results are still sub-optimal for clinical use. With the goal of advancing the state-of-the-art in automatic classification, the Grand Challenge on BreAst Cancer Histology images (BACH) was organized in conjunction with the 15th International Conference on Image Analysis and Recognition (ICIAR 2018). BACH aimed at the classification and localization of clinically relevant histopathological classes in microscopy and whole-slide images from a large annotated dataset, specifically compiled and made publicly available for the challenge. Following a positive response from the scientific community, a total of 64 submissions, out of 677 registrations, effectively entered the competition. The submitted algorithms improved the state-of-the-art in automatic classification of breast cancer with microscopy images to an accuracy of 87%. Convolutional neuronal networks were the most successful methodology in the BACH challenge. Detailed analysis of the collective results allowed the identification of remaining challenges in the field and recommendations for future developments. The BACH dataset remains publicly available as to promote further improvements to the field of automatic classification in digital pathology.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The BACH challenge was organized to push forward methods for automatic classification of breast cancer biopsies using clinical hematoxylin-eosin stained histopathological images. </LI> <LI> A large public dataset, composed of 400 microscopy images and 30 whole-slide images, was specifically compiled for the BACH challenge. </LI> <LI> A total of 64 methods were submitted, out of 677 registration, and a detailed comparative analysis was carried out for the methods with higher accuracy scores. </LI> <LI> Several submitted algorithms performed better than the state-of-the-art in terms of accuracy (top score of 87%). </LI> <LI> Convolutional neural networks dominated the submissions, and was the method of choice in the algorithm that won the challenge. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Damping Ratios of Pristine Composite Beam and Constrained Layer Damped Composite Beam of Equal Stiffness

Ramadas Chennamsetti,Avinash Hood,Siddlingappa Guruprasad,Sajal Roy,Makarand Joshi 한국정밀공학회 2013 International Journal of Precision Engineering and Vol. No.

Constrained layer damping is one of the passive techniques to control amplitude of vibration of structural components. In the present work an attempt has been made to quantify and compare damping ratios of composite-rubber-composite sandwich beam with that of pristine composite beam having nearly the same flexural stiffness and range of frequency of vibration from 20 Hz to 100 Hz. Length and thickness of sandwich and pristine beams in order to have the same flexural stiffness and desired frequency range of vibration were specifically designed. The damping ratio of each sandwich and pristine composite beams were measured experimentally using logarithmic decay and half-power bandwidth techniques.

AO Lamb Mode Radiation Characteristics of Air-Coupled Transducers in Isotropic Plates

Ramadas Chennamsetti,Irfan Khan 한국정밀공학회 2015 International Journal of Precision Engineering and Vol. No.

The fundamental anti-symmetric Lamb mode (Ao) radiation characteristics of air-coupled transducers in isotropic (aluminium) plateswere measured experimentally for the first time. To evaluate the radiation characteristics, experiments were performed by fixing theposition of one of the transducers (either transmitter or receiver) and then moving other one (either receiver or transmitter) alongthe circumference of a circle, whose radius was equal to that of the distance of separation between the transducers. Experiments wereconducted to evaluate the radiation pattern of 100 kHz, 200 kHz and 500 kHz air-coupled transducers in one mm and three mm thickaluminium plates. It is interesting to note that, Ao Lamb mode radiation pattern emitted by air-coupled transducers in isotropic platesis characterised by Gaussian curve.

Root anatomical traits influence water stress tolerance in rice (Oryza sativa L.)

Manikanta Chennamsetti Lakshmi Naga,Beena Radha,Rejeth R. 한국작물학회 2022 Journal of crop science and biotechnology Vol.25 No.4

Though a lot of research was carried out pertaining to above ground traits in relevance to mitigating adverse efects of water stress; however, root traits play a dynamic role in acquisition of water and mineral nutrients from the soil suggesting greater emphasis for a sustainable crop production under water stress environments. For instance, under water defcit, plasticity in below ground traits viz., root morphology and anatomy determine the water acquisition capacity of the plant. In the current study, initially 35 genotypes were evaluated for various morpho-physiological and yield traits at 100 and 50% available soil moisture content. Results of Principal Component Analysis reveals that under stress, stomatal conductance, and photosynthetic rate in PC1, plant height and leaf temperature in PC2 attributed to maximum variation. A narrowed down sample set of six genotypes comprising three tolerant and three susceptible were further evaluated for anatomical and morphological investigations on roots at their respective booting stage. Root length, diameter, stele diameter, metaxylem number, width and ratio of stele diameter to root diameter ratio were varying signifcantly (p<0.05) for drought tolerant and susceptible genotypes. This study revealed that drought tolerant genotypes had better root plasticity in terms of metaxylem number and stele diameter compared to susceptible genotypes. This provided maintenance cost under water-limited conditions and produced a satisfactory yield by efcient uptake and utilization of available soil moisture.

Changes Observed in Ao Mode Due to Rotational Misalignment of Air-Coupled Transducers in Isotropic Plates

Ramadas Chennamsetti,Irfan Khan,Avinash Hood,Makarand Joshi 한국정밀공학회 2013 International Journal of Precision Engineering and Vol. No.

Misalignments are a major concern, when air-coupled ultrasonic probes are deployed for transmission and reception of Lamb waves. Misalignments between the air-coupled probes result in reduction in amplitude and change in arrival time of the Lamb waves. This reduction in amplitude can give a false alarm in Non-destructive Testing (NDT) applications, if amplitude is the criterion for flaw or damage detection. In the present work, one of the probe’s (transmitter or receiver) position was kept fixed, and the other probe was rotated to introduce a misalignment termed ‘rotational misalignment’. This rotation had violated the co-planarity condition,resulting in reduction in amplitude of the received fundamental anti-symmetric mode (Ao) in an isotropic material plate. Interestingly,variation in amplitude of the Ao mode with the rotational misalignment angle revealed that, at certain angular locations, there exists a local maximum and local minimum resembling sync function. Subsequently, the angular location of occurrence of these is attributed to dispersion characteristics of the Ao mode.

Propagation of Ao Mode through the Front Edge of a Delamination: Numerical and Experimental Studies

Rakesh Kumar Singh,Ramadas Chennamsetti 한국정밀공학회 2014 International Journal of Precision Engineering and Vol. No.

Numerical and experimental studies carried out on the propagation of ultrasonic Lamb wave and its interaction with the front edgeof a delamination in a cross-ply and unidirectional composite laminates are presented in this paper. When the fundamental antisymmetricLamb mode (Ao) is incident at the leading (front) edge of a delamination, it undergoes reflection and transmission into thesub-laminates. Numerical simulations carried out on the interaction of the Ao mode with the edge of a semi-infinite delaminationrevealed that during this interaction, So mode is generated and propagate as AoSo (propagation of the So mode due to the incidentAo mode) mode in the top and bottom sub-laminates along with the incident Ao mode, which propagates as AoAo (propagation of theAo mode due to the incident Ao mode) mode. Transmission factors and power transmission coefficients of AoAo and AoSo modes onan assortment of excitation frequencies – 150 kHz, 175 kHz, 200 kHz and 225 kHz, and thickness ratios were computed. Experimentalvalidation of results arrived through numerical simulations, was also carried out employing air-coupled ultrasonic transducers.