Oxygen

Plant hemoglobins: Oxygen handlers critical for nitrogen fixation

Hemoglobins, key components of our blood, are ancient proteins with well-known roles in oxygen transport and respiration in animals. Hemoglobins are also present in plants and bacteria, but until now the physiological role of plant hemoglobins has been unclear. A group of researchers reveal this week that one such mysterious plant hemoglobin serves to assist in the fixation of nitrogen in the roo...

Why do insects stop 'breathing'? To avoid damage from too much oxygen, say researchers

A new study investigating the respiratory system of insects may have solved a mystery that has intrigued physiologists for decades: why insects routinely stop breathing for minutes at a time. Challenging previous theories, researchers at UC Irvine and Humboldt University propose that insects such as grasshoppers, moths, butterflies, some types of fruit flies, beetles and bugs close off th...

Yeast Network Prevents Damage By Oxygen Radicals

Reactive oxygen species (ROS), or 'oxygen radicals', have been identified as major contributors to signs of premature aging, increased cancer prevalence linked to inflammation-associated syndromes and a variety of human diseases. Now scientists at the University of California, San Diego Branch of the Ludwig Institute for Cancer Research (LICR) have identified a key network of DNA repair and cell...

Low oxygen likely made Great Dying worse, greatly delayed recovery

The biggest mass extinction in Earth history some 251 million years ago was preceded by elevated extinction rates before the main event and was followed by a delayed recovery that lasted for millions of years. New research by two University of Washington scientists suggests that a sharp decline in atmospheric oxygen levels was likely a major reason for both the elevated extinction rates and the v...

Oxygen increase caused mammals to triumph, researchers say

The first, high resolution continuous record of oxygen concentration in the earth's atmosphere shows that a sharp rise in oxygen about 50 million years ago gave mammals the evolutionary boost they needed to dominate the planet, according to Paul Falkowski, Rutgers professor of marine science and lead author of a paper published Sept. 30 in the journal Science. Falkowski and his colleague...

Hopkins researchers discover genetic switch that turns off an oxygen-poor cell's combustion engine

Johns Hopkins researchers have discovered a previously unrecognized role played by the gene HIF-1 as it helps cell survive when a lack of oxygen decreases production of an energy-rich molecule called ATP and increases production of toxic molecules. ATP supplies energy the cell needs to perform each of its many chemical reactions and tasks, and in this way acts as the "currency" for the cell's en...

Don't hold your breath: Carp can manage without oxygen for months

How long can you hold your breath? Scientists at the University of Oslo have recently discovered how the Crucian Carp, a close relative of the goldfish, is able to live for months without oxygen. The researchers hope that understanding how some animals cope with a lack of oxygen might give clues as to how to solve this problem in humans. "Anoxia related diseases are the major causes of dea...

Heart has enough oxygen to survive hypothermia, CPR crucial

Researchers from Norway may have ruled out insufficient oxygen supply to the heart as the critical variable in whether a mammal's heart survives while in a hypothermic state. Writing in the July issue of the American Journal of Physiology-Heart and Circulatory Physiology, researchers found no significant difference in the amount of oxygen available to the heart between rats exposed to one...

Steep oxygen decline halted first land colonization by Earth's sea creatures

Vertebrate creatures first began moving from the world's oceans to land about 415 million years ago, then all but disappeared by 360 million years ago. The fossil record contains few examples of animals with backbones for the next 15 million years, and then suddenly vertebrates show up again, this time for good. The mysterious lull in vertebrate colonization of land is known as Romer's Gap...

Technology for monitoring fetal oxygen during labor offers no apparent benefit

A new technology for measuring blood oxygen levels of a baby during labor--expected to provide information useful for preventing birth complications--offers no apparent benefit, report researchers in a National Institutes of Health research network. The technology, known as fetal oxygen saturation monitoring, was designed for use along with electronic fetal monitoring, which tracks the fet...

Giant insects might reign if only there was more oxygen in the air

The delicate lady bug in your garden could be frighteningly large if only there was a greater concentration of oxygen in the air, a new study concludes. The study adds support to the theory that some insects were much larger during the late Paleozoic period because they had a much richer oxygen supply, said the study's lead author Alexander Kaiser. The study, "No giants today: tracheal oxy...

Seals protect brain, conserve oxygen by turning off shivering response on icy dives

Seals shiver when exposed to cold air but not when diving in chilly water, a finding that researchers believe allows the diving seal to conserve oxygen and minimize brain damage that could result from long dives. The researchers presented the study at The American Physiological Society's conference "Comparative Physiology 2006: Integrating Diversity," in Virginia Beach, Va., October 8-11....

Genetically engineered blood protein can be used to split water into oxygen and hydrogen

Scientists have combined two molecules that occur naturally in blood to engineer a molecular complex that uses solar energy to split water into hydrogen and oxygen, says research published today in the Journal of the American Chemical Society. This molecular complex can use energy from the sun to create hydrogen gas, providing an alternative to electrolysis, the method typically used to s...

Breathing easy: When it comes to oxygen, a bug's life is full of it

Because of new imaging technology, researchers are getting a better understanding of a physiological paradox: how insects, which have a respiratory system built to provide quick access to a lot of oxygen, can survive for days without it. The insect respiratory system is so efficient that resting insects stop taking in air as they release carbon dioxide, according to research by Stefan K. H...

Need oxygen? Cells know how to spend and save

Researchers at Johns Hopkins have discovered how cells fine-tune their oxygen use to make do with whatever amount is available at the moment. Too little oxygen threatens life by compromising mitochondria that power it, so when oxygen is scarce, cells appear to adjust by replacing one protein with an energy-efficient substitute that "is specialized to keep the motor running smoothly even as...