Wednesday, April 10, 2013

Purple sea urchins evolve in a flash to survive growing acidity

Jackie Sones

Purple urchins have been shown to adapt rather quickly to caustic ocean conditions.

By Tanya Lewis
LiveScience

Mushrooming carbon-dioxide levels are leading to caustic ocean conditions, but some species, like the purple sea urchin, have the ability to adapt to this changing environment, a new study shows.

Researchers grew purple sea urchins?(Strongylocentrotus purpuratus) ? which are echinoderms (a group that also includes sea stars and brittle stars) with spiky protrusions made of calcium carbonate ? in the lab. The invertebrates were grown under conditions mimicking expected future levels of the greenhouse gas carbon dioxide.

In response to high carbon dioxide levels, the urchins showed substantial changes in the proportion of genes involved in regulating their cells' pH (the degree of acidity) and skeletal development.

The oceans are expected to become increasingly acidic this century as carbon dioxide gets pumped into the atmosphere and, ultimately, the seas. The acidity is particularly problematic for organisms that must create shells from calcium carbonate, because the shells are more likely to dissolve under acidic conditions. [Gallery: Stunning Images of Sea Urchins]

"The big unanswered question is, if and how marine organisms will be able to respond to ocean acidification," said Melissa Pespeni, an evolutionary biologist at Indiana University and lead author of the study, published Monday?in the journal Proceedings of the National Academy of Sciences.

Eric Sanford

Beautiful urchin metamorphs.

Pespeni and her colleagues bred adult sea urchins, collected from the Pacific Ocean between central Oregon and Southern California, in tanks exposed to regular carbon-dioxide levels or elevated levels of carbon dioxide forecasted to occur as a result of climate change. The scientists measured the growth and genetic variation of the urchin larvae during their first week of development, a time when the larvae are still free-swimming blobs undergoing major skeletal growth.

The immature urchins showed few visible changes in growth and development, but there were noticeable differences in the abundance of certain genes. The urchins exposed to higher carbon-dioxide levels showed changes in genes involved in promoting growth, producing minerals and keeping pH within a range that's tolerable to them. In comparison, the urchins exposed to current carbon-dioxide levels showed only random genetic variation.

The findings demonstrate that the high-carbon-dioxide environment was exerting natural selection on the urchin larvae: Only the "fittest" ? those with the most advantageous genes ? survived. It was exciting to see that the urchins could adapt, Pespeni told LiveScience.

"If any organism were able to adapt and evolve, it would be the sea urchins, because they live in an environment where they're experiencing daily changes in pH," she said.

The urchins are very long-lived and have more genetic variability than any other species ? including humans, she added. Consequently, the urchins have a broad arsenal for responding to changes in their environment. The findings give scientists hope that organisms like the purple sea urchin might be able to adapt to rising carbon-dioxide levels, but it's unclear whether other organisms will be so flexible.

Moreover, increasing levels of greenhouse gases?is just one of many changes associated with climate change. It would be interesting, Pespeni said, to find out how the urchins would adapt to other stressors, such as temperature.

Despite the ability of some species to adapt to climate change, it is still important to preserve large, robust populations of various animals, Pespeni and her colleagues stressed.

Follow Tanya Lewis on Twitter?and Google+.?Follow us @livescience, Facebook?and Google+. Original article on?LiveScience.com.

Copyright 2013 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Source: http://feeds.nbcnews.com/c/35002/f/653377/s/2a841ddc/l/0Lscience0Bnbcnews0N0C0Inews0C20A130C0A40C0A90C17672170A0Epurple0Esea0Eurchins0Eevolve0Ein0Ea0Eflash0Eto0Esurvive0Egrowing0Eacidity0Dlite/story01.htm

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Volcanic ash triggers plankton bloom

The 2010 Icelandic volcanic eruption, which disrupted European flights, also had a "significant but short-lived" impact on ocean life, a study shows.

Ash from the Eyjafjallajokull volcano deposited dissolved iron into the North Atlantic, triggering a plankton bloom.

The authors said it was good fortune they were at sea at the time as it provided a unique opportunity to sample the ocean during a volcanic eruption.

The findings appear in the Geophysical Research Letters journal.

In April 2010, the eruption sent an ash plume several kilometres into the atmosphere, causing ash to deposited across up to 570,000 sq km of the North Atlantic Ocean.

The five-week volcanic activity was still ongoing when a team of researchers arrived in the Iceland Basin region aboard a research vessel.

"Our study was unique in the sense that we were the first to undertake sampling at sea of volcanic ash deposition and the chemical and biological effects in the surface ocean," explained lead author Eric Achterberg from the National Oceanography Centre Southampton, UK.

"In addition, we were able to sample the ocean region again a few months after the eruption and observe the changes since the eruption.

"The opportunity to sample during the eruption and also a couple of months after the event allowed us to obtain a unique insight into the effects of the ash deposition on the biology and chemistry of the Iceland Basin."

Iron deficiency

Three years earlier, the team had shown that the production of phytoplankton - microscopic plants that form a key component of marine food chains - was limited by the availability of dissolved iron, which was essential for the tiny plants' growth.

Prof Achterberg told BBC News what the in-situ team was able to record: "Biological experiments showed that the volcanic ash released the iron that stimulated phytoplankton growth.

"The effect of the volcanic ash inputs were nevertheless short-lived as the extra iron supplied by the volcano resulted in rapid biological nitrate removal, thereby causing nitrogen limitation of the phytoplankton population."

So while the additional dissolved iron triggered an earlier-than-usual phytoplankton bloom, as the metal triggered growth in a greater number of phytoplankton cells, the bloom was only 15-20% larger than normal because the growth was limited by the amount of available nitrogen, another vital ingredient required for the organisms to develop.

As well as playing an important role in food chains, phytoplankton also absorb carbon dioxide from the atmosphere.

Oceans are considered to be one of the planet major players in the global carbon cycle, but the carbon uptake in the region where the eruption occurred has limited capacity.

"The high latitude North Atlantic Ocean is a globally important ocean region, as it is a sink for atmospheric carbon dioxide and an area where deep water formation takes place," Prof Achterberg observed.

"A limit to the availability of iron in this region means that the ocean is less efficient in its uptake of atmospheric carbon dioxide."

However during the bloom triggered by the ash deposits from the eruption, the team recorded that it was a shortage of nitrogen that limited the size of the phytoplankton bloom and - as a result - the volume of carbon dioxide uptake.

Prof Achterberg concluded: "The 2010 Eyjafjallajokull eruption therefore resulted in a significant but short lived perturbation to the biogeochemistry of the Iceland Basin."

Source: http://www.bbc.co.uk/news/science-environment-22045941#sa-ns_mchannel=rss&ns_source=PublicRSS20-sa

david wilson

Tuesday, April 9, 2013

Missing hiker: "I was in a big dream"

ORANGE, Calif. (AP) ? One of two hikers who got lost in the Southern California wilderness last week said Monday she remembers little about her four-day ordeal because she began hallucinating on the first night after the pair finished the three bottles of water they had and darkness fell.

Kyndall Jack, 18, and her friend, Nicolas Cendoya, went missing on March 31 in Cleveland National Forest after wandering off a trail during what they thought would be a short day hike. The pair had picked the hike on the popular Holy Jim Trail almost at random after deciding they wanted to climb to a mountaintop to "touch the clouds," Jack said at a brief news conference.

She said the last thing she remembers is fighting off an animal with Cendoya after darkness fell, but she does not recall how the two got separated or what she did between then and her rescue. She hallucinated she was being eaten by a python, she tried to eat rocks and dirt, and thought that tree twigs were straws from which she could suck water.

"I honestly didn't even know I was missing, I didn't know I was gone, I didn't know anything was going on," she said. "I just thought I was in a big dream."

Jack was plucked by helicopter from a tiny rocky outcropping on a near-vertical cliff Thursday, after searchers followed her cries for help across a canyon and up several dried-up waterfalls. She was severely dehydrated, could not move one arm and complained of shortness of breath and pain in her chest and legs, rescuers said at the time.

Her mouth was so full of dirt the first man to reach her was afraid she would choke if he gave her water.

Cendoya, 19, had been rescued the night before after a volunteer searcher heard him call out from chest-high brush not far from where Jack was found. He was released from the hospital Sunday and the two have since seen each other and tried to make sense of their hallucinations with little luck.

Jack, who was expected to be released late Monday, has frostbite in her left hand and swelling, cuts and bruises on her legs that still make walking difficult.

She sat in a wheelchair and appeared weak during a brief news conference outside the University of Irvine, California Medical Center. The ends of her fingernails were ragged and still coated with dirt and she wore a bandage on one arm, moccasins on her swollen feet and a neon yellow hospital bracelet that said "Fall Risk."

The hike started out well but things quickly went wrong when they left the trail, she recalled.

"We just saw a good place and we were like, 'Oh, we're just going to scale the mountain here," she said.

They realized as darkness fell that they were lost and nowhere near the mountaintop and Cendoya called 911 twice on his dying cellphone.

In the second call, he and Jack can be heard having a tense conversation as the operator tries to determine where exactly they are in the 720-square-mile national forest ? a vast wilderness that runs smack up against the suburban comforts of southeastern Orange County.

"Yeah, we wandered off the trail. We wandered off the trail," Cendoya told the operator. "I don't even know if we'll make it to the morning because we have no water."

At one point, Jack can be heard in the background telling Cendoya there is something moving in the wilderness and at another point, she cries out for help as the operator tells the pair deputies are on foot searching for them.

"We don't hear them, but we screamed and my echo went out for miles," Cendoya says during the nine-minute call.

Jack said Monday that she panicked as the darkness closed in around them. She tried to climb a tree and use her lighter to provide a signal for rescuers, but she dropped it. She thinks she remembers fighting off some type of animal with Cendoya before the two began to slip in and out of consciousness ? but that, too, could have been a dream.

"I started to get like an anxiety attack and I started throwing up and I just lost it. I just went in and out of consciousness after the 911 call," she said.

"We just kept telling each other, 'Don't close your eyes. Don't fall asleep,'" she said.

Jack vaguely remembers "scooting" down a steep embankment ? likely the cliff where she was found ? but she isn't sure when she did that and how she managed to cling to the rocks for so long.

The teen warned other hikers to pack more water and supplies and not stray off the trail.

She also said she'd like to thank two of her rescuers in person: The first reserve sheriff's deputy who reached her and the paramedic who airlifted her to safety in a harness.

Another Orange County reserve sheriff's deputy who participated in the rescue slipped and fell 10 feet, hitting his chest on a rock before falling another 50 feet and hitting his head. He suffered cuts to his head, a punctured lung, broken ribs and other injuries. He was released from intensive care over the weekend and upgraded to fair condition.

Source: http://news.yahoo.com/calif-hiker-4-days-missing-felt-dream-234658888.html

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Anesthetic linked to brain cell death in newborn mice

Apr. 8, 2013 ? Exposure to the anesthetic agent isoflurane increases "programmed cell death" of specific types of cells in the newborn mouse brain, reports a study in the April issue of Anesthesia & Analgesia, official journal of the International Anesthesia Research Society (IARS).

With prolonged exposure, a common inhaled anesthesia eliminates approximately two percent of neurons in the cortex of newborn mice. Although its relevance to anesthesia in human newborns remains to be determined, the study by Dr George K. Istaphanous and colleagues of Cincinnati Children's Hospital Medical Center provides unprecedented detail on the cellular-level effects of anesthetics on the developing brain.

Isoflurane Exposure Increases 'Programmed Death' of Brain Cells

In the study, seven-day-old mice were exposed to isoflurane for several hours. After exposure, sophisticated examinations were performed to assess the extent of isoflurane-induced brain cell death, including the specific types, locations, and functions of brain cells lost.

Isoflurane exposure led to widespread increases programmed cell death, called apoptosis, throughout the brain. Although cell loss was substantially higher after isoflurane exposure, the cell types lost were similar to the cells lost in the apoptosis that is part of normal brain maturation. In both cases, mainly neurons were lost. Neurons are the cells that transmit and store information.

The rate of cell death in the superficial cortex -- the thick outer layer of the brain -- was at least eleven times higher in isoflurane-exposed animals than seen with normal brain maturation. Overall, approximately two percent of cortical neurons were lost after isoflurane exposure. Astrocytes, another major type of cortical brain cells, were less affected by anesthetic exposure.

Relevance to Anesthesia in Human Newborns Is Unclear -- For Now

A growing body of evidence suggests that isoflurane and similar anesthetics may have toxic effects on brain cells in newborn animals and humans. "However, neither the identity of dying cortical cells nor the extent of cortical cell loss has been sufficiently characterized," according to Dr Istaphanous and colleagues.

The new study provides detailed information on the extent and types of brain cell loss resulting from prolonged isoflurane exposure in newborn mice. It's unclear whether the two percent brain cell loss induced in the experiments would lead to any permanent damage -- in previous studies, newborn isoflurane-exposed mice showed no obvious brain damage long after the exposure.

It can't be assumed that isoflurane causes similar patterns of cellular damage in human newborns requiring general anesthesia, Dr Istaphanous and coauthors emphasize. Some studies have linked early-life exposure to anesthesia and surgery to later behavioral and learning abnormalities. Other studies have found no adverse affects on children exposed to anesthetics during vulnerable times of brain development. Further research on the selective nature and molecular mechanisms of isoflurane-induced brain cell death would be needed to determine the relevance of the experimental findings, if any, to human infants undergoing anesthesia.

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The above story is reprinted from materials provided by International Anesthesia Research Society (IARS), via Newswise.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.


Journal Reference:

  1. George K. Istaphanous, Christopher G. Ward, Xinyu Nan, Elizabeth A. Hughes, John C. McCann, John J. McAuliffe, Steve C. Danzer, Andreas W. Loepke. Characterization and Quantification of Isoflurane-Induced Developmental Apoptotic Cell Death in Mouse Cerebral Cortex. Anesthesia & Analgesia, 2013; 116 (4): 845 DOI: 10.1213/ANE.0b013e318281e988

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Source: http://feeds.sciencedaily.com/~r/sciencedaily/mind_brain/child_development/~3/R07mepKF7pY/130408152741.htm

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Cabela's to Hire 200 to Staff New Green Bay, Wis., Store

Applications being accepted now, according to general manager Steve Farone.

Cabela?s Green Bay, Wisconsin Store

Cabela?s Green Bay, Wisconsin Store

Cabelas

Cabelas

SIDNEY, Neb. --(Ammoland.com)- Cabela?s Incorporated, the World?s Foremost Outfitter of hunting, fishing and outdoor gear, plans to hire approximately 200 full-time, part-time and seasonal employees to staff its new Green Bay, Wis., store scheduled to open this summer.

Applications are being accepted now and interviews will begin April 22, continuing through April 26.

To apply, visit www.cabelas.jobs, click on ?Apply Now,? then ?United States Jobs,? and select ?Green Bay.? Follow instructions to log in. Applications must be submitted online. Applying does not guarantee an interview.?http://tiny.cc/jdp8uw

Most employees are expected to come from Green Bay and the surrounding area. Typically, Cabela?s attracts applicants with detailed knowledge about the outdoors and an aptitude for customer service.

?Cabela?s is looking for employees who will deliver legendary customer service, and who will be excited about sharing their passion and knowledge of the outdoors with our many loyal customers across the area,? said Steve Farone, general manager of the new store.

The 100,000-square-foot store is located at 1499 Lombardi Ave N near Lambeau Field in the Village of Ashwaubenon in Brown County. It is Cabela?s third Wisconsin store, joining the Richfield and Prairie du Chien locations. In addition to thousands of quality outdoor products, the store will feature a mountain replica, aquarium, indoor archery range, dynamic wildlife displays, Gun Library, Bargain Cave, Deli, Fudge Shop and Sportsman?s Hall of Fame displaying Wisconsin trophy animal mounts.

Currently, Cabela?s operates 43 stores across the United States and Canada. The company has announced plans to open an additional 12 stores by the end of 2014.

www.cabelas.com

About Cabela?s Incorporated
Cabela?s Incorporated, headquartered in Sidney, Nebraska, is a leading specialty retailer, and the world?s largest direct marketer, of hunting, fishing, camping and related outdoor merchandise. Since the Company?s founding in 1961, Cabela?s? has grown to become one of the most well-known outdoor recreation brands in the world, and has long been recognized as the World?s Foremost Outfitter?. Through Cabela?s growing number of retail stores and its well-established direct business, it offers a wide and distinctive selection of high-quality outdoor products at competitive prices while providing superior customer service. Cabela?s also issues the Cabela?s CLUB? Visa credit card, which serves as its primary customer loyalty rewards program. Cabela?s stock is traded on the New York Stock Exchange under the symbol ?CAB?.

Source: http://www.ammoland.com/2013/04/cabelas-to-hire-200-to-staff-new-green-bay-wis-store/

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7-Year-Old Boy Fighting Brain Cancer Scores 69-Yard Touchdown

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Source: http://www.wildcatnation.net/forum/showthread.php?105833-7-Year-Old-Boy-Fighting-Brain-Cancer-Scores-69-Yard-Touchdown

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