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Background Grade and histotype of ovarian carcinomas are often used as surrogates of molecular subtypes. We examined factors affecting pathologists' reproducibility in two prospective studies. Methods Two pathologists independently reviewed slides from 459 incident ovarian cancers in the Nurses' Health Study (NHS) and NHSII. We described agreement on tumor characteristics using percent agreement and Cohen's standard kappa (κ) coefficients. We used logistic regression, with disagreement as the outcome, to evaluate the contribution of case and tumor characteristics to agreement. Results Inter-rater agreement was 95% (κ = 0.81) for carcinoma versus borderline, 89% (κ = 0.58) for grade and 85% (κ = 0.71) for histotype. Inter-rater grading disagreement was higher for non-serous histotypes (OR = 4.66, 95% CI 2.09–10.36) and lower for cancers with bizarre atypia (OR = 0.13, 95% CI 0.04–0.38). Agreement with original pathology reports was 94% (κ = 0.73) for carcinoma versus borderline, 78% (κ = 0.60) for histotype, and 79% (κ = 0.24) for grade. Grading disagreement was significantly lower for tumors with ‘solid, pseudoendometrioid or transitional’ (SET) architecture (OR = 0.08, 95%CI 0.01–0.84). Date of original diagnosis, hospital type, number of slides available for review, tumor stage, and slide quality were not related to agreement. Conclusion Overall, inter-rater agreement for tumor type and grade for archival tissue specimens was good. Agreement between the consensus review and original pathology reports was lower. Factors contributing to grading disagreement included non-serous histotype, absence of bizarre atypia, and absence of SET architecture.

During the last decades the strategy to define the optimal Electric Arc Furnaces (EAF) electrical operational parameters has been constantly evolving. Foaming slag practice is currently used to allow high power factors that ensures higher energy efficiency. However, this performance depends on strict electric arc stability control. Control strategies for these are normally defined for alternating current furnaces (AC EAF) and are based on intrusive and highly expensive systems. In this work we analyze the variation of the magnetic field vector around the direct current EAF (DC EAF) and its relationship with arc stability. We propose a cheap stability control system with no installation or integration requirements and thus, easily implementable to both AC and DC EAFs. To this end we have built a non-intrusive and low-cost 3-axis Hall-effect sensor that can be mounted neighboring the furnace’s electrical bars. The sensor allows acquiring the magnetic field magnitude and orientation that provides a newly defined arc stability factor metric. This proposed Arc Stability Index has been compared with three different alternative well established and more expensive measurement methodologies obtaining with similar results. The proposed index serves as a closed loop signal to the electrical regulation for controlling the arc voltage, ensuring the most convenient arc length that guaranties non-instabilities. The new system was developed and industrially validated at two different DC EAF’s in ArcelorMittal demonstrating an improvement of 6.7 kWh per Liquid steel ton during the evaluated period and a time reduction of 1.1 min per heat over the current standard procedure. Additional validation tests were also carried out also in ArcelorMittal AC EAF proving the capability of this technology for both AC and DC of furnaces. Partial financial support of this work by the Basque Govern-ment (Hazitek AURRERAB ZE-2017/00009 and FASIN ZE-2016/0016 Projects) is gratefully acknowledged.