Highlighted publications | Vascular Observations through Research on Technology and Exercise Lab

This work made use of our custom LBNP chamber that was designed for work inside the box during negative pressure. We found that there is a profound venous response to LBNP in the lower limbs, which was expected based on the known fluid distribution effects of negative pressure. There was no impact of exercise pre-conditioning to temper this response.
This work was done as part of Skye Ling's senior undergraduate thesis project.

Zaheer A, Peckett K, Pereira TJ, Acker S, Au JS. The consequences of high-flexion postures on arterial wave reflections. J Human Hypertens 2026, 40(1):18-22.

This work extended previous studies in the lab and sought to determine if large arteries might dictate the peripheral wave reflection response. In brief, they don't!
This work was done as part of Aida Zaheer's senior undergraduate thesis project.

Cohen JN & Au JS. The Blueprint: Contemporary venous physiology and measurement. Am J Physiol Heart Circ Physiol 2025, 329(4):H801-H814.

In this modern take on venous physiology, we outline the current regulatory factors involved in the control of venous blood flow, as well as emerging imaging technologies that surpass existing techniques for better measurement in humans.
This work was done as part of Jeremy Cohen's PhD thesis.

This work investigated a hands-free probe holder to measure blood velocity during exercise. This was a technically challenging protocol, attempting to affix a probe holder above small diameter arteries during cycling exercise at increasing intensities. The probe holder was excellent for non-active upper limb blood velocity measurement, but did not outperform manual scanning of the lower limbs during cycling.

This work defined an upstream distance whereby the femoral bifurcation remains uncontaminated from multidirectional blood flow using next-generation ultrasound techniques.
This work was done as part of Jeremy Cohen's PhD thesis.

This work explored how the internal jugular vein conforms to fluid shifts and used next-generation ultrasound imaging to detail what happens to blood when fluid shifts towards the head. This work is related to the previously noted risk of thromboembolism in astronauts during long-duration spaceflight.
This work was done as part of Jeremy Cohen's PhD thesis.

Al-Bakry D, Athaide CE, Pathmarajan R, Kuhn T, Middleton L, Au JS. Short-term vascular responses to spring and fall daylight savings time shifts. Am J Physiol Heart Circ Physiol 2024, 326(5):H1138-H1145.

This short report examined whether there are short-term changes to arterial health during the transition into and out of Daylight Savings Time in Canada. This is one of the only human studies to measure how the body responds to a societal schedule shift.
This work was done as part of Dara Al-Bakry's senior undergraduate thesis.

This study examined what happens to the vascular system after a period of prolonged sitting and how exercise or standing countermeasures can alleviate some of the cardiovascular burden during periods of sedentary behaviour.
This work was done as part of Chloe Athaide's MSc thesis.

Bryans CG*, Gopaul J*, Athaide CE*, Pugh CJA, Au JS. The influence of activity and sex on carotid artery longitudinal wall motion. Appl Physiol Nutr Metab 2024, 49(3):385-394.

This cross-sectional study evaluated whether following the Canadian Physical Activity Guidelines is associated with more positive health of the carotid arteries. This study was conducted shortly after alleviation of COVID-19 related research pauses.
This work was done as part of Carol Bryans' senior undergraduate thesis.

This short report explored a potential new venous mechanism that helps blood return from the periphery back towards the heart. The central idea is that arteries that run parallel to greater veins help push blood on each pulsation. The effect is theorized to only occur when venous valves are active.
This work was done as part of Jeremy Cohen's PhD thesis.

Athaide CE, Cohen JN, Stevens KA, Robertson AD, Au JS. Heating-induced peripheral limb microvascular vasodilation reduces arterial wave reflection. J Appl Physiol 2023, 134(5):1232-1239.

This original article sought to investigate where arterial wave reflections originate in humans. As opposed to previous thinking that the muscular legs are quite important, we didn't show any differences between vasodilating the arm vs the leg to decrease wave reflection. Peripheral vasodilation seems to be important, but not the investigated limb, as per our results.
This work was done as part of Chloe Athaide's MSc thesis.

Athaide CE Spronck B, Au JS. Physiological basis for longitudinal motion of the arterial wall. Am J Physiol Heart Circ Physiol 2022, 322(5):H689-H701.

This review summarizes the most up-to-date information on the physiology and regulation of carotid artery longitudinal wall motion.
This work was done as part of Chloe Athaide's MSc independent study.

This study examined how the heart, pulse, and arteries respond to a common type of arrythmia in a healthy male. Pre-mature ventricular contracts are 'extra beats' that occur when the left ventricle contracts before electrical activity arrives from the left atrial. This unique situation results in work of the left ventricle without actually ejecting much blood into the body.
Forwards arterial wall motion remained unchanged despite large deviations in local blood velocity and backwards wall motion mirrored changes in pulse pressure, blood velocity, and cardiac motion, thereby revising our original hypothesis of the control of longitudinal wall motion.
This work was done as part of Kailey Steven's undergraduate independent study.