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We describe a technique, using thin lines of triplet-state He2* molecular tracers created by femtosecond-laser field ionization of helium atoms, for visualizing the flow of the normal fluid in superfluid 4He, together with its application to thermal counterflow in a channel. We show that, at relatively small velocities, where the superfluid is already turbulent, the flow of the normal fluid remains laminar, but with a distorted velocity profile, while at a higher velocity there is a transition to turbulence. The form of the structure function in this turbulent state differs significantly from that found in types of conventional turbulence. This visualization technique also promises to be applicable to other fluid dynamical problems involving cryogenic helium. [ABSTRACT FROM AUTHOR]

Background: Since the emergence of neurosurgery as a distinct specialty ∼100 years ago in Canada, it took >40 years for Canadian women to enter the field in the province of Quebec, and longer in the other provinces., Methods: We provide a historical overview of Canadian women in neurosurgery, from the early pioneers to the modern-day leaders and innovators in the field. We also define the current participation of women in Canadian neurosurgery. Chain-referral sampling, historical books, interviews, personal communications, and online resources were used as data sources., Results: Our historical review highlights the exceptional journey and unique experiences of female neurosurgeons, describes their achievements, and identifies career obstacles and enabling factors. We also incorporate comments from Canadian female neurosurgeons, both retired and in active practice, addressing gender inequities in the field, and provide advice and encouragement to the new generations to come. Despite the achievements of these female trailblazers, women represent a small proportion of the Canadian neurosurgery trainees and the active workforce, in stark contrast to the increasing number of women in medical school., Conclusions: To the best of our knowledge, this study represents the first historical overview of female women neurosurgeons in Canada. Providing a historical context will help us to better understand the important role of women in modern neurosurgery, identify persistent gender issues in the field, and provide a vision for aspiring female neurosurgeons., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Hypercalcemia was identified in a canine patient with a benign vaginal leiomyoma. Subsequent diagnostic workup did not reveal hypercalcemia of malignancy. Surgical resection of the leiomyoma resulted in a conversion to normocalcemic status. Although rare, hypercalcemia of benignancy should be considered in a patient in which hypercalcemia is identified via clinical pathology.