Tag: missing
Scientists observe elusive missing step in photosynthesis’ final stage
Researchers at the SLAC National Accelerator Laboratory and Lawrence Berkeley National Laboratory (along with collaborators in Sweden, Germany and the UK) have shed new light on the final step of photosynthesis. They observed in atomic detail how Photosystem II, a protein complex found in plants, undergoes a transformation that leads to the loss of an extra oxygen atom. Scientists believe the discoveries will help provide a roadmap for optimizing clean energy sources. “It’s really going to change the way we think about Photosystem II,” said Uwe Bergmann, scientist and professor at the University of Wisconsin-Madison, who co-authored the paper.
Researchers took “extremely high-resolution images” of different stages of the process (at room temperature), giving them new insight into specifically how and where the oxygen is produced. Baseball can provide a simple (if somewhat forced) metaphor to illustrate the process. “The center cycles through four stable oxidation states, known as S0 through S3, when exposed to sunlight,” SLAC explains. “On a baseball field, S0 would be the start of the game when a player on home base is ready to go to bat. S1-S3 would be players on first, second, and third.” Based on this metaphor, a batter making contact to advance the runners signifies the complex absorbing a sunlight photon. “When the fourth ball is hit, the player slides into home, scoring a run or, in the case of Photosystem II, releasing one molecule of breathable oxygen.” It’s that final stage (S4, between third base and sliding home in our metaphor) that they imaged for the first time, where two oxygen atoms bond to release an oxygen molecule, revealing additional steps previously unseen.
The video below illustrates the team’s process and discoveries.
“Most of the process that produces breathable oxygen happens in this last step,” said Vittal Yachandra, a scientist at Berkeley Lab and co-author of the paper, published inNature. “But there are several things happening at different parts of Photosystem II and they all have to come together in the end for the reaction to succeed. Just like how in baseball, factors like the location of the ball and the position of the basemen and fielders affect the moves a player takes to get to home base, the protein environment around the catalytic center influences how this reaction plays out.”
The researchers expect an X-ray upgrade later this year to shed more light on the process. It will use a repetition rate of up to a million pulses per second, up from the 120 per second used in this experiment. “With these upgrades, we will be able to collect several days’ worth of data in just a few hours,” Bergmann said. “We will also be able to use soft X-rays to further understand the chemical changes happening in the system. These new capabilities will continue to drive this research forward and shed new light on photosynthesis.”
The team believes the results will help them “develop artificial photosynthetic systems that mimic photosynthesis to harvest natural sunlight to convert carbon dioxide into hydrogen and carbon-based fuels.” Jan Kern, another co-author and scientist at Berkley Lab, said, “The more we learn about how nature does it, the closer we get to using those same principles in human-made processes, including ideas for artificial photosynthesis as a clean and sustainable energy source.”
This article originally appeared on Engadget at https://www.engadget.com/scientists-observe-elusive-missing-step-in-photosynthesis-final-stage-214947146.html?src=rss
Human remains in woodland identified as man who went missing in 2002
Body found in search for teenager who went missing in River Thames
Missing teenager: Body found in the River Thames
Bones Found in Lake Mead Finally Identified as Missing Man
Human remains unveiled in Lake Mead’s low water levels last year have finally been identified as a Las Vegas man who went missing years ago, local authorities said this week.
Urgent police search to find missing girls, aged 13 and 14, believed to be together
Tragedy as body of missing teen, 18, found in river months after they vanished – leaving devastated family ‘in pieces’
A DEVASTATED family have been left “in pieces” after the body of a missing teenager was found in a river months after vanishing.
Alex Bendall, 18, known as Alice, was reported missing from Dorchester, Dorset, on February 12.
The body of the missing teenager was found in a river[/caption]
She went missing two months ago from Dorchester[/caption]
Cops said a body had been found in the River Frome in the area of Lubbecke Way in Dorchester at around 3pm on Saturday.
Alex, who was known to their family by the pronouns she/her, had been due to start a new job caring for people with dementia and had a driving test booked in the days after vanishing.
In an appeal last month, Alex’s father Paul Bendall, 60, said: “It’s like someone had put a bomb in the family and we’re just in pieces.
“We just want you home with the family so we can just be complete again.”
Her mother Vicky said: “You have so much to live for. It’s out of character to go wandering without telling us where she could be.”
Extensive searches of the area involving National Police Air Service, Dorset Search and Rescue, Wiltshire Search and Rescue, Dorset Search Dogs, Hampshire Search & Rescue Dogs and Wessex 4×4 had taken place in the weeks after their disappearance.
The death is not being treated as suspicious and the coroner has been informed as well as Alex’s heartbroken family.
A spokesperson for Dorset Police said: “A body sadly found in a river in Dorchester is believed to be that of a missing teenager from the Dorchester area.
“The report of the discovery at the River Frome in the area of Lubbecke Way was received by Dorset Police at around 3pm on Saturday.
“Although formal identification has not yet taken place, it is believed to be 18-year-old Alex Bendall, who was reported missing on Sunday, February 12.”
Police ‘extremely worried’ about father and daughter who have been missing for 10 days
Resident Evil 2 and 3 patch adds missing raytracing options back to the games
Capcom has released a patch for Resident Evil 2 and Resident Evil 3 that returns raytracing to the game.
Earlier this week, the company released an update for the remakes which removed raytracing options without an explanation.
Turns out, the removal was unintended, and Capcom has now patched raytracing back into the games.