Ocean deoxygenation is an emerging hazard for marine ecosystems and a fingerprint of anthropogenic change. Interior ocean oxygen concentrations respond to changes in ventilation that supply the demand biogeochemical processes consume oxygen. A better understanding their regional importance would improve confidence Earth System Model projections, which underpin ecosystem risk vulnerability asses...

BACKGROUND Aerobic adaptations following interval training are supposed to be mediated by increased local blood supply. However, knowledge is scarce on the detailed relationship between exercise duration and local post-exercise blood supply and oxygen availability. This study aimed to examine the effect of five different exercise durations, ranging from 30 to 240 s, on post-exercise muscle oxyg...

Myocardial ischemia, or lack of oxygen, is caused by an imbalance between oxygen supply and oxygen demand in the heart. This imbalance is usually due to an inability to increase coronary blood flow in response to increased myocardial oxygen consumption. The inability to increase coronary blood flow is often related to atherosclerosis of the large coronary arteries, which leads to a progressive ...

Vertebrate lungs have long been thought to have evolved in fishes largely as an adaptation for life in hypoxic water. This view overlooks the possibility that lungs may have functioned to supply the heart with oxygen and may continue to serve this function in extant fishes. The myocardium of most vertebrates is avascular and obtains oxygen from luminal blood. Because oxygen-rich pulmonary blood...

From an evolutionary point of view, an overriding biological priority is to ensure offspring survival. Oxygen is essential for the growing fetus, and during pregnancy the fetus has an increasing demand for oxygen. If the oxygen supply to the fetus is threatened, it is likely that compensatory mechanisms are activated. Impaired development of the placenta in early pregnancy is assumed to be the ...

The brain's ability to function at high levels of metabolic demand depends on continuous oxygen supply through blood flow and tissue oxygen diffusion. Here we present a visualized experimental and methodological protocol to directly visualize microregional tissue hypoxia and to infer perivascular oxygen gradients in the mouse cortex. It is based on the non-linear relationship between nicotinami...

The coronary arteries supply the heart muscle (myocardium) with oxygen and nutrients. According to current scientific views, low-grade inflammation causes lipid deposits in the artery wall, which may create plaques. This condition, atherosclerosis, occurs predominantly in larger arteries, including coronary arteries. The subsequent narrowing of the artery restricts blood flow to the myocardium,...

Adaptation to lowering oxygen levels (hypoxia) requires coordinated downregulation of metabolic demand and supply to prevent a mismatch in ATP utilization and production that might culminate in a bioenergetic collapse. Hypoxia diminishes ATP utilization by downregulating protein translation and the activity of the Na-K-ATPase. Hypoxia diminishes ATP production in part by lowering the activity o...

Growing on rooting media other than soils in situ -i.e., substrate-based growing- allows for higher yields than soil-based growing as transport rates of water, nutrients, and oxygen in substrate surpass those in soil. Possibly water-based growing allows for even higher yields as transport rates of water and nutrients in water surpass those in substrate, even though the transport of oxygen may b...