(National Science Foundation) The appearance of oxygen in the Earth’s atmosphere probably did not occur as a single event, but as a long series of starts and stops, according to geoscientists who investigated rock cores from the FAR DEEP project.

(American Geological Institute) Law enforcement may have a new crime-solving tool, courtesy of geoscientists. About five years ago, scientists coined the word “isoscape” to describe a new kind of map: a spatial distribution of stable isotope ratios (from elements such as carbon, hydrogen, oxygen, nitrogen and strontium) in different parts of the world, based on known ways that these isotopes behave in the environment. As EARTH explores in “Cold Case Files: Forging Forensic Isoscapes,” the potential usefulness of isoscapes is wide-ranging and thrilling.

At rest, the brain takes up oxygen and carbohydrate at an ∼6:1 ratio. Exercise increases systemic lactate availability reducing this to as little as 1.7:1 despite a ∼20% increase in cerebral metabolic rate for oxygen (CMRO₂), thus indicating a disproportionate increase of carbohydrate metabolism. Underlining mechanisms and metabolic fate for the augmented lactate uptake are unknown. This meta-analysis examines whether adrenergic activation explains the increased lactate uptake, cerebral lactate release following cerebral activation compensates for the extra carbohydrate uptake during exercise, and cerebral lactate uptake spares glucose as fuel. Ten studies (n=96) measuring arteriovenous differences for lactate, glucose, and oxygen and cerebral blood flow were included. Cerebral lactate uptake increased during brain activation by whole-body exercise compared to the resting state. Unlike glucose, lactate uptake is proportional to its arterial concentration but is unaffected by sympathetic activity. Following exercise, significant cerebral lactate released as arterial lactate levels decreased, which may balance the surplus lactate uptake in the brain during physical activity in the long term. Finally, cerebral glucose uptake was reduced by ∼25% in relation to CMRO₂ when cerebral lactate uptake increased, suggesting, in part, preferential lactate consumption during activation. This meta-analysis favors the notion that cerebral lactate uptake is mainly passively governed by its availability, but when lactate is available, lactate supplements glucose and supports an increase in cerebral energy metabolism in an activity-dependent manner.—Rasmussen, P., Wyss, M. T., Lundby, C. Cerebral glucose and lactate consumption during cerebral activation by physical activity in humans. Full Text

September 2011The FASEB Journalvol. 25 no. 9 2865-2873

(University of California – Riverside) University of California, Riverside researchers report that the ancient deep ocean was not only devoid of oxygen but also rich in iron, a key biological nutrient, for nearly a billion years longer than previously thought–right through a key evolutionary interval that culminated in the first rise of animals. “We will need to rethink all of our models for how life-essential nutrients were distributed in the ocean through time and space,” the authors say.

(Massachusetts Institute of Technology) Research from MIT suggests O2 may have been made on Earth hundreds of millions of years before its debut in the atmosphere, keeping a low profile in “oxygen oases” in the oceans. The MIT researchers found evidence that tiny aerobic organisms may have evolved to survive on extremely low levels of the gas in these undersea oases.

(Massachusetts Institute of Technology) Research from MIT suggests O2 may have been made on Earth hundreds of millions of years before its debut in the atmosphere, keeping a low profile in “oxygen oases” in the oceans. The MIT researchers found evidence that tiny aerobic organisms may have evolved to survive on extremely low levels of the gas in these undersea oases.

(University of California – San Francisco) Elderly women who suffer from sleep apnea — characterized by disrupted breathing and sleep and a reduction in the intake of oxygen — are about twice as likely to develop dementia in the next five years as those without the condition, according to a multicenter study led by researchers from the University of California, San Francisco.

(University of California – Los Angeles) UCLA scientists report a connection between climate fluctuations and the habitability of marine ecosystems by modeling the expansion and contraction of low-oxygen zones that are dangerous for ocean life. The team found that the size of low-oxygen ocean regions is extremely sensitive to changes in their depth caused by oscillations in climate.

(MWW Group) A recent study published in Panminerva Medica reveals that a Pycnogenol and Coenzyme Q10 (CoQ10) combination (PycnoQ10) taken by stable heart failure patients as an adjunct to medical treatment naturally strengthens the heart, increasing the blood volume ejected with each beat. As a consequence, the oxygen-rich blood supply to the organs improves, and patients become more physically energetic. Furthermore, blood pressure, heart rate and respiratory rates were improved among patients.

(MWW Group) A recent study published in Panminerva Medica reveals that a Pycnogenol and Coenzyme Q10 (CoQ10) combination (PycnoQ10) taken by stable heart failure patients as an adjunct to medical treatment naturally strengthens the heart, increasing the blood volume ejected with each beat. As a consequence, the oxygen-rich blood supply to the organs improves, and patients become more physically energetic. Furthermore, blood pressure, heart rate and respiratory rates were improved among patients.