An opportunity has arisen for a Postdoctoral Researcher in the Gray Institute for Radiation Oncology and Biology. This post will join Dr Vincenzo DAngiolella?s research team, which focuses on the maintenance of genome stability in normal and cancer cells.
The successful candidate will undertake state-of-the-art molecular, cell biological and biochemical techniques ...
Getting blisters on a run is the most annoying of injuries. They hurt. They can keep you sidelined when you're trying to train. They heal slowly. Worst of all: They're not even cool enough to brag about. So let's see how we can prevent them from happening in the first place. More »
Feb. 13, 2013 ? High school students whose friends' average grade point average (GPA) is greater than their own have a tendency to increase their own GPA over the course of a year, according to research published February 13 in the open access journal PLOS ONE by Hiroki Sayama from Binghamton University and his collaborators from Maine-Endwell High School in Endwell, New York, including four high school student researchers.
Previous studies have shown that a student's social network can influence obesity, emotional state and other cognitive traits and behavior. However, this is the first to examine how peer groups can influence academic progress over time. To assess this effect, the researchers first asked eleventh grade students to categorize their peers as best friends, friends, acquaintances, strangers or relatives. The researchers then mapped how students performed in school relative to their peer group, and correlated their social network with the change of their academic performance over time.
They found that students' whose friends were performing better academically were more likely to improve their own scores over time. The opposite effect was also seen: When their friends' GPA were lower, a given student's GPA was more likely to decrease as well.
The authors also found that the strongest link between a student's GPA change and that of their peers was likely to be with those they had ranked as friends, rather than best friends or acquaintances. They state, "While most educators already know the importance of social environment for a student's academic success, our study presents the first quantitative supporting evidence for such empirical knowledge."
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Journal Reference:
Deanna Blansky, Christina Kavanaugh, Cara Boothroyd, Brianna Benson, Julie Gallagher, John Endress, Hiroki Sayama. Spread of Academic Success in a High School Social Network. PLoS ONE, 2013; 8 (2): e55944 DOI: 10.1371/journal.pone.0055944
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.
It is Valentine?s Day and I want to talk to you about how you smell. This will not be a discussion about how your musky, earthy scent attracts a mate. No, we need to have a conversation about how your urinous, acidic odor might drive one away.
There are ways to safeguard against the Valentine?s Day faux pas of smelly underarms. Think about what you will wear to celebrate the holiday. I?m going to make this simple ? avoid polyester.
It seems like it would be easy to adhere to such advice, but consider possible Valentine?s Day agendas: a bike ride for two, a hike to a secluded picnic spot, a candle-lit prix frixe dinner. Athletic wear is an olfactory nightmare, but even a romantic, flowy blouse could ruin a date. Sporty or dressy, garments made from synthetic fibers smell worse than anything else in the closet. The reason why can be understood by examining the fibers? chemical and physical properties.
Rachel McQueen is an assistant professor at the University of Alberta. Her research primarily focuses on the development and retention of odor in textiles. Because human odor profiles and fabric fiber structures are so complex, it is difficult to pick apart all the factors that lead to a garment retaining odor.
So Dr. McQueen started with the basics, answering the question: Does polyester actually have greater odor intensity compared to natural fibers? ?A lot of people would probably think, ?So what, I knew that, because when I go to the gym my polyester T-shirt stinks to high heaven,?? says Dr. McQueen. But she wanted scientific proof to validate these anecdotal stories. And she wanted to determine whether more odor intensity was associated with more garment bacteria.
While working on her doctorate at the University of Otago in New Zealand, Dr. McQueen and her colleagues performed a statistical analysis of bacterial population found on odorous garments. What they discovered flies in the face of what is commonly believed to be associated with textile odor.
I was in a stinky situation myself two weeks ago while attending ScienceOnline2013. This is no ordinary conference. Highlights of the Wednesday evening opening, at the North Carolina Museum of Natural Sciences, included finding out what kind of microorganisms live on your face and under your arms. While passing time, waiting to get sampled, I made small talk with fellow attendees, strangers, informing them that I do not wear deodorant. This topic of conversation made perfect sense in the context of the experiment for which we were all anxious volunteers. Later, I regretted the decision.
I don?t have a meaningful, philosophical explanation for why I don?t wear deodorant. One day I just stopped. That was five years ago and after a week without it I realized I didn?t always need it, so now I rarely use it.
It turns out some individuals are blessed with odor-free armpits. A research group in Hamburg, Germany identified a gene critical for odor formation. A single mutation in the gene, ABCC11, leads to complete odor loss in the carrier. Human body odor forms when bacteria consumes protein rich fluids secreted from glands in the armpits (among other places) leaving behind vile fatty acids, vinegar?s big brothers. The gene mutation means these odor molecules never become part of the secretion in the first place.
Unfortunately, few people with this mutation realize they are carriers. A study last month conducted in the UK found that 78% of people who carry the mutated gene still wear deodorant.
This is not surprising, considering that for 100 years we have been trained to wear deodorant. Like Pavlovian dogs, our societal response to puberty?s signals is doling out antiperspirant. Sarah Everts uncovered the history of antiperspirant in this story for Smithsonian magazine which explores how deodorant and antiperspirant became social norms.
All of this pit lit gives credence to my anti-antiperspirant stance, but unfortunately I don?t posses the ABCC11 mutation. The gene mutation also affects ear wax; you may be a carrier if yours is dry. Mine is quite sticky; besides, sometimes I smell. Just as I did the third morning of ScienceOnline2013 when I realized, mid fist pump, while screaming, ?I?m a African? during the nine o?clock convergence (I told you this was no ordinary conference), that I had B.O. This is a disconcerting notion when you are surrounded by people you barely know, many of whom you have informed that deodorant application is not in your hygiene regimen. So when your associates catch a whiff of acidic odor, like Fifi the kitty in a Pepe Le Pew cartoon, there will be no doubt as to its origin.
I was too far from the hotel to return and change. So I kept my elbows pinned to my sides and convinced myself that the shirt would air out as I moved. At the end of the day I put the shirt to my nose; it was offensive. Then I dug my travel shirt out from the bottom of my suitcase. It smelled fine, like my laundry detergent. One shirt (made of cotton) had endured 18 hours of wear, including travel: on a train, on a plane, in a warm taxi, in a van full of people, through a lemur center (Oh my god, you want to talk about stench!) and by foot, several blocks. The other shirt (made of polyester) was foul within an hour. There had to be a scientific explanation.
When Dr. McQueen and her colleagues studied microbial populations on garments composed of different materials the findings were surprising. ?Bacteria survives a lot longer on wool then on polyester and cotton,? says Dr. McQueen. Which is contrary to what was expected and ? regardless of her findings ? what we are still led to believe.
If odor molecules are the leftovers when bacteria eats, then it is presumed that a garment with less bacteria will have less odor. Because of this line of thinking, antimicrobial coatings are being researched and produced for athletic and healthcare attire. Dr. McQueen laments that even Merino wool manufactures will tout the fabric?s antimicrobial properties on their websites. Dr. McQueen laughs, ?It?s like, hang on, there?s bacteria all over your body, there?s bacteria all over a sheep?s bodies. It doesn?t make sense.?
The difference in surface morphology between the two fiber types is what is more likely to be responsible. Surface morphology describes the terrain of a fiber. A natural fiber like cotton or wool is highly textured compared to a manmade fiber which has a smooth surface. On a larger scale, these surface properties result in polyester having a sheen and wool being matte.
Dr. McQueen likes to picture wool as activated carbon. ?The complexity of wool and its structure has a lot of different potential chemical binding sites,? she says. Not only is it possible for odor molecules to bind fairly strongly to the wool fibers, but the intricacy of natural fibers physically limit the ability of odor molecules to escape the fabric. If odor molecules don?t escape, then we can?t smell them. Odor molecules do not penetrate a polyester fiber and since there is only a weak surface interaction the odor molecules are free to travel into an olfactory system and register as unpleasant.
Rachel McQueen has further experiments to conduct to prove her hypothesis. She admits, ?This is a really under studied area: odor on textiles.? In her ongoing research she hopes to identify the mechanisms for the interactions between odor molecule and fibers.
Textile science has taught has this: if the cutie from your running club invites you on a Valentine?s Day Five Miler, accept without fear of a stench. Just by pass all the high-tech fabrics in your drawer (at least for the layer closest to your skin) and don some cotton. Happy Valentine?s Day!
WASHINGTON (AP) ? Uncompromising and politically emboldened, President Barack Obama urged a deeply divided Congress Tuesday night to embrace his plans to use government money to create jobs and strengthen the nation's middle class. He declared Republican ideas for reducing the deficit "even worse" than the unpalatable deals Washington had to stomach during his first term.
In his first State of the Union address since winning re-election, Obama conceded economic revival is an "unfinished task," but he claimed clear progress and said he prepared to build on it as he embarks on four more years in office.
"We have cleared away the rubble of crisis, and we can say with renewed confidence that the state of our union is strong," Obama said in an hour-long address to a joint session of Congress and a television audience of millions.
With unemployment persistently high and consumer confidence falling, the economy remains a vulnerability for Obama and could disrupt his plans for pursuing a broader agenda, including immigration overhaul, stricter gun laws and climate change legislation.
Still, fresh off a convincing re-election win, Obama made clear in his remarks that he was determined to press his political advantage against a divided, defensive and worried Republican Party. Numerous times he urged Congress to act quickly on his priorities ? but vowed to act on some issues on his own if they do not.
Obama also announced new steps to reduce the U.S. military footprint abroad, with 34,000 American troops withdrawing from Afghanistan within a year. And he had a sharp rebuke for North Korea, which launched a nuclear test just hours before his remarks, saying, "Provocations of the sort we saw last night will only isolate them further."
In specific proposals for shoring up the economy in his second term, an assertive Obama called for increased federal spending to fix the nation's roads and bridges, the first increase in the minimum wage in six years and expansion of early education to every American 4-year-old. Seeking to appeal for support from Republicans, he promised that none of his proposals would increase the deficit "by a single dime" although he didn't explain how he would pay for his programs or how much they would cost.
In the Republican response to Obama's address, rising GOP star Marco Rubio of Florida came right back at the president, saying his solution "to virtually every problem we face is for Washington to tax more, borrow more and spend more."
Sen. Rubio said presidents of both parties have recognized that the free enterprise system brings middle-class prosperity.
"But President Obama?" Rubio said. "He believes it's the cause of our problems."
Still, throughout the House chamber there were symbolic displays of bipartisanship. Rep. Tammy Duckworth, D-Ill., arrived early and sat with Sen. Mark Kirk, R-Ill., just returned in January nearly a year after suffering a debilitating stroke. As a captain in the National Guard, Duckworth lost both her legs while serving in Iraq in 2004.
A few aisles away, the top two tax writers in Congress, Rep. Dave Camp, R-Mich., and Sen. Max Baucus, D-Mont., sat together.
But as a sign that divisions still remain, three of the most conservative Supreme Court justices skipped Obama's speech. Six of the nine attended. Missing were Justices Clarence Thomas, Antonin Scalia and Samuel Alito.
Jobs and growth dominated Obama's address. Many elements of his economic blueprint were repacked proposals from his first term that failed to gain traction on Capitol Hill.
Standing in Obama's way now is a Congress that remains nearly as divided as it was during the final years of his first term, when Washington lurched from one crisis to another.
The president implored lawmakers to break through partisan logjams, asserting that "the greatest nation on Earth cannot keep conducting its business by drifting from one manufactured crisis to the next."
"Americans don't expect government to solve every problem," he said. "They do expect us to forge reasonable compromise where we can."
Yet Obama offered few signs of being willing to compromise himself, instead doubling down on his calls to create jobs by spending more government money and insisting that lawmakers pay down the deficit through a combination of targeted spending cuts and tax increases. But he offered few specifics on what he wanted to see cut, focusing instead on the need to protect programs that help the middle class, elderly and poor.
He did reiterate his willingness to tackle entitlement changes, particularly on Medicare, though he has ruled out increasing the eligibility age for the popular benefit program for seniors.
Republicans are ardently opposed to Obama's calls for legislating more tax revenue to reduce the deficit and offset broad the automatic spending cuts ? known as the sequester ? that are to take effect March 1. The president accused GOP lawmakers of shifting the cuts from defense to programs that would help the middle class and elderly, as well as those supporting education and job training.
"That idea is even worse," he said.
Obama broke little new ground on two agenda items he has pushed vigorously since winning re-election: overhauling the nation's fractured immigration laws and enacting tougher gun control measures in the wake of the horrific massacre of school children in Newtown, Conn. Yet he pressed for urgency on both, calling on Congress to send him an immigration bill "in the next few months" and insisting lawmakers hold votes on his gun proposals.
"Each of these proposals deserves a vote in Congress," he said. "If you want to vote no, that's your choice."
Numerous lawmakers wore green lapel ribbons in memory of those killed in the December shootings in Connecticut. Among those watching in the House gallery: the parents of 15-year-old Hadiya Pendleton, shot and killed recently in a park just a mile from the president's home in Chicago, as well as other victims of gun violence.
On the economy, Obama called for raising the federal minimum wage from $7.25 to $9 by 2015. The minimum wage has been stagnant since 2007, and administration officials said the increase would strengthen purchasing power. The president also wants Congress to approve automatic increases in the wage to keep pace with inflation.
Looking for common ground anywhere he could find it, Obama framed his proposal to boost the minimum wage by pointing out that even his GOP presidential rival liked the idea. He said, "Here's an idea that Gov. Romney and I actually agreed on last year: Let's tie the minimum wage to the cost of living, so that it finally becomes a wage you can live on."
Obama also renewed his calls for infrastructure spending, investments he sought repeatedly during his first term with little support from Republicans. He pressed lawmakers to approve a $50 billion "fix it first" program that would address the most urgent infrastructure needs.
Education also figures in Obama's plans to boost American competitiveness in the global economy. Under his proposal, the federal government would help states provide pre-school for all 4-year-olds. Officials did not provide a cost for the pre-school programs but said the government would provide financial incentives to help states.
Among the other initiatives Obama is proposing:
? A $1 billion plan to create 15 "manufacturing institutes" that would bring together businesses, universities and the government. If Congress opposes the initiative, Obama plans to use his presidential powers to create three institutes on his own.
? Creation of an "energy security trust" that would use revenue from federal oil and gas leases to support development of clean energy technologies such as biofuels and natural gas
? Doubling of renewable energy in the U.S. from wind, solar and geothermal sources by 2020.
? Launching negotiations on a free trade agreement between the U.S. and European Union
Obama also called on Congress to tackle the threat of climate change, another issue that eluded him in his first term. The president pledged to work with lawmakers to seek bipartisan solutions but said if Capitol Hill doesn't act, he'll order his Cabinet to seek steps he can take using his presidential powers.
Taking a swipe at those who question the threat of global warming, Obama said, "We can choose to believe that Superstorm Sandy, and the most severe drought in decades, and the worst wildfires some states have ever seen were all just a freak coincidence. Or we can choose to believe in the overwhelming judgment of science - and act before it's too late."
Tackling voters' rights issues, Obama announced the creation of a commission that will seek to make it easier and faster for people to cast ballots on Election Day. He used as an example the story of 102-year-old Desiline Victor, a Florida woman who waited in line to vote for several hours during the November election. Victor attended Tuesday's speech as a guest of the first lady and was applauded heartily by the lawmakers.
Obama also called on Congress to pass legislation giving the government more power to combat the rapidly growing threat of cyberattacks. And, as a down payment on that, the president announced that he has signed an executive order to fight electronic espionage through the development of voluntary standards to protect networks and computer systems that run critical infrastructure.
___
Associated Press writer Nancy Benac contributed to this report.
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Watching Brooke play soccer, basketball or run a 5k, you would never think about Special Olympics. She is a true athlete in every aspect of the word.
Brooke has been part of Special Olympics for the past six years, and in her words, ?loved every minute of it.? Basketball is her favorite, but she plays a mean game of soccer as well. When asked why she favored basketball, she said, ?because of the rush of the game and you know that if you mess up, you have teammates that can help you win back the basketball.? ?
We as a company cover all aspects of Special Olympics New Jersey and Unified Sports is a part of their programs. Brooke participates in Unified Basketball and Unified Soccer. When asked if she felt if there was a difference in Unified sports as opposed to the other Special Olympics sports Brooke said, ?There is a difference because you are given the opportunity not only to play your sport and meet new people but you?re given the opportunity to see your friends outside of the sport that you play. They plan events where you are able to see your teammates and friends in Unified as you watch an Eagles game, meet an author, or even in a race.?
What she would like people to know about Special Olympics is that it is not about special players playing with others like them; it is about people who have disabilities playing sports to be given the chance to play a sport they love and meet others who have the same love. Brooke continued to say, ?Before I started to play in Special Olympics, I played in other basketball teams but I wasn?t considered good because I wasn?t competitive or wasn?t skilled with the ball. Then I started to go to Bankbridge, and started to make new friends, and I signed up for basketball again. I practiced once a week with my team and also practiced everyday at home. I started to become better with dribbling and shooting.?
Brooke?s special message: ?Special Olympics has not only made me more competitive on the court but it has also helped me in life outside of sports. It has helped me to have more confidence, be more sociable and to believe in myself. Now, whenever I step onto a court for a game the players know to watch out for me.?
Deb Creighton, Brooke?s Mom also had a message: ?Brooke is our hero! I must first state that she comes from a very competitive family that values a win. We have always enjoyed ?gym time? and Brooke has been involved since she was in a rock a roo. It is no surprise that she loves the orange ball! She has heard everything there is to hear about the game in different venues, but never did she ?feel? it until becoming a member of Special Olympics. Brooke did attempt to join a recreation league team in the 5th grade only to have a whistle blown every time she touched the ball for one reason or another, so that became a very frustrating experience. However, when she had the opportunity to play at her new school with the Special Olympics, all the years of watching exploded with skill and confidence. Brooke views each practice and game with the level of intensity unmatched by most ?typical athletes.? This is something that unfortunately is often misunderstood by many. These special athletes live by their motto, ?Let me win, but if I cannot win, let me be brave in the attempt.? When the game is over they move on to the next practice or game and don?t fret over what can?t be changed, but they do care! These athletes don?t want games to end in a tie and let all, ?be happy.? They know who played better and who deserved the victory. They don?t want a sympathy vote. They want to earn the ?W.? Typical athletes could learn a lot from watching these games. Brooke participated in the Rowan Unified League last year for basketball and soccer and words can?t express how awesome that was for my girl. The first thing on Brooke?s Christmas list was a Rowan Sweatshirt! The Unified Sports Program is an amazing program that is educating many people that never knew they needed education! Again?. we have a lot to learn from these special athletes.
Watch our Hero and you just may learn a little something about the game!?
Deb Creighton summed up the Unified program at Rowan University and other Universities and schools in New Jersey and elsewhere in the country.
Over the weekend, New York-based redditor Brian Maffitt aimed a projector—playing The Lorax—at the blizzard which struck the east coast and photographed the result. The images are a beautiful and psychedelic take on the pure-white flakes that fell. More »
WASHINGTON (AP) ? President Barack Obama's decision to bring home within a year about half of the 66,000 U.S. troops now in Afghanistan will shrink the force to the size he found it when he entered the White House vowing to reinvigorate a stalemated war.
Still to be decided: how many troops will remain beyond 2014, when the U.S.-led combat mission is scheduled to end. The stated goal is to prepare Afghanistan's army and police to handle the Taliban insurgency largely on their own by then.
Obama determined that his war goals could be achieved by bringing 34,000 U.S. troops home by this time next year, officials said, leaving somewhere between 32,000 and 34,000 to support and train Afghan forces. That is about the number in Afghanistan when he took office in January 2009; in a series of moves designed to reverse the Taliban's battlefield momentum, he tripled the total American force before starting to scale it back in the summer of 2011.
Obama's new move coincides with a major shake-up in his war command. Gen. Joseph Dunford took over Sunday for Gen. John Allen as the commander of all allied forces in Afghanistan, and Defense Secretary Leon Panetta is planning to retire as soon as his replacement is confirmed. Obama has nominated former Sen. Chuck Hagel to take the Pentagon post, and the Senate Armed Services Committee voted 14-11 Tuesday to advance the nomination to the full Senate for a vote possibly later this week.
Obama's decision also reflects Obama's determination to wind down a war that is the longest in America's history. He has many other security problems to consider around the globe ? from North Korea's development of nuclear weapons to civil war in Syria to the worrisome spread of al-Qaida affiliated terrorist groups in the Middle East and North Africa.
In advance of Obama's announcement in his State of the Union speech, the White House said the president made his decision about 2013 troop reductions based on recommendations by the military and his national security advisers, as well as consultations with allies such as Britain and Germany and talks with Afghan President Hamid Karzai.
A Pentagon statement said Panetta fully supports Obama's troop reductions.
In farewell remarks to Pentagon employees, Panetta said Tuesday he is confident that the war strategy is on track.
"We will be able to transition over these next two years to a point where the Afghans themselves can govern and secure themselves," he said.
The White House did not spell out the pace at which the 34,000 troops will be withdrawn over the coming year. Defense officials said it's likely that the bulk of them will be kept through summer. The officials spoke on condition of anonymity because details of the withdrawal had not been announced.
Private analysts are divided on the wisdom of accelerating the withdrawal of American forces. Michael O'Hanlon of the Brookings Institution wrote that he believes the current U.S. troop level should remain until autumn, when a seasonal lull in Taliban activity usually begins. "The president should now be patient with what happens over the next eight months," O'Hanlon wrote in an opinion piece for Politico, adding that Dunford needs time to consolidate progress in eastern Afghanistan.
The U.S. is still finalizing plans for the size and scope of its military presence after the allied combat mission ends in December 2014.
Stephen Biddle, a professor of international affairs at George Washington University, said the decision on post-2014 force levels is more important than the pace of 2013 withdrawals.
"The real issue is what you're ultimately going to draw down to ? what does the end of this road look like, not the weigh stations," Biddle said.
Officials have said the White House is considering a range of options that would leave between 5,000 and 10,000 troops beyond 2014, but it also is hoping for help from NATO allies. Those troops would limit their missions to training Afghan troops and hunting down terrorists.
Obama discussed the next phases of the drawdown with Karzai during a meeting in Washington last month, their first since Obama's re-election. They agreed to accelerate their timetable for putting Afghan forces in the lead combat role nationwide, moving that transition up from the summer to the spring.
A persistent worry is that pulling out of Afghanistan too quickly will leave the battle-scarred country vulnerable to collapse. In a worst-case scenario, that could allow the Taliban to regain power and revert to the role they played in the years before 9/11 as protectors of al-Qaida terrorists bent on striking the U.S.
Many Americans, however, are weary of the war, according to public opinion polls, and are skeptical of any claim that Afghanistan is worth more U.S. blood. Registered voters are roughly split between those who say the U.S. should remove all troops and those who favor leaving some troops in place for counterterrorism efforts, according to a recent Fox News poll.
___
Associated Press writer Lolita C. Baldor and AP Broadcast correspondent Sagar Meghani contributed to this report.
Rice University lab shows how blood vessels regroup after strokePublic release date: 11-Feb-2013 [ | E-mail | Share ]
Contact: David Ruth david@rice.edu 713-348-6327 Rice University
By thinking of cells as programmable robots, researchers at Rice University hope to someday direct how they grow into the tiny blood vessels that feed the brain and help people regain functions lost to stroke and disease.
Rice bioengineer Amina Qutub and her colleagues simulate patterns of microvasculature cell growth and compare the results with real networks grown in their lab. Eventually, they want to develop the ability to control the way these networks develop.
The results of a long study are the focus of a new paper in the Journal of Theoretical Biology.
"We want to be able to design particular capillary structures," said Qutub, an assistant professor of bioengineering based at Rice's BioScience Research Collaborative. "In our computer model, the cells are miniature adaptive robots that respond to each other, respond to their environment and pattern into unique structures that parallel what we see in the lab."
When brain cells are deprived of oxygen a condition called hypoxia that can lead to strokes they pump out growth factor proteins that signal endothelial cells. Those cells, which line the interior of blood vessels, are prompted to branch off as capillaries in a process called angiogenesis to bring oxygen to starved neurons.
How these new vessels form networks and the shapes they take are of great interest to bioengineers who want to improve blood flow to parts of the brain by regenerating the microvasculature.
"The problem, especially as we age, is that we become less able to grow these blood vessels," Qutub said. "At the same time, we're at higher risk for strokes and neurodegenerative diseases. If we can understand how to guide the vessel structures and help them self-repair, we are a step closer to aiding treatment."
First, they need to understand how individual cells respond to stimuli. To model the process in a computer requires rules, Qutub said. In these simulations, each cell is a "state machine," a unit that goes from one "state" to the next in time based on input. In the case of these endothelial cells, the input comes from vascular endothelial growth factor and/or brain-derived neurotrophic factor, proteins that encourage angiogenesis.
"There's a memory in each of these cells that helps define how they emerge into these very elaborate vasculature structures," she said. The cells that quickly differentiate into tip and stalk cells follow particular rules to advance, grow, divide and branch, depending on input from growth factors and from neighboring cells that can dictate how far and how fast they develop.
For instance, she said, in a chain of endothelial cells, a tip cell at its maximum length can only continue to migrate if the stalk cell immediately behind grows and pushes it forward. Similarly, the team set rules for branching and changes in direction, as well as an "idle" state, all based on observation of real vessel growth.
The researchers modeled a set of endothelial cells growing from a sphere and exposed them to simulated growth factors. They let them grow for what, in real life, would be a period of 24 hours, but in the computer took fractions of a second. They ran tens of thousands of simulations to see how the cells would migrate, proliferate and branch under various conditions.
The next step was to figure out which of the computer simulations matched actual behavior. Qutub's lab cultured spheres of human umbilical vein endothelial cells in collagen scaffolds, exposed them to growth factors and took microscope images as they developed networks over several days.
They compared these images with the simulations. The closest matches of which there are only a few amid thousands of simulations became the basis for a refined set of rules.
"We know how cells are connected as a function of the growth factors, and there are very distinct patterns to the way these networks are organized," Qutub said. "So when we compare the simulations with the assays, we find parallels that let us classify what we see in the real networks. This gives us a paradigm where we can start to think of actually programming real cells with chemical signaling.
"It opens up a lot of doors," she said. "Now we can think about changing things in the cells or giving them drugs that target pathways and growth factors to induce a particular vasculature structure."
###
Byron Long, a postdoctoral research associate in the Qutub Group, is lead author of the paper. Co-authors are Rice undergraduates Rahul Rekhi and Jiwon Jung and Amada Abrego, an undergraduate student at the Monterrey Institute of Technology, Mexico, who took part in the Rice Summer Undergraduate Research Program in Biosciences and Bioengineering, funded by the Howard Hughes Medical Institute, and has a complimentary appointment to the Qutub Lab.
The research was funded in part by a National Academies Keck Future Initiatives grant, a Hamill Innovation Award and a National Science Foundation CAREER award.
Read the abstract at http://dx.doi.org/10.1016/j.jtbi.2012.11.030
See a short video of simulated network growth at http://youtu.be/7Qly07KMp-s
Follow Rice News and Media Relations via Twitter @RiceUNews
Related Materials:
Qutub Systems Biology Lab: http://www.qutublab.rice.edu/index.html
Multiscale Models of Angiogenesis: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3077679/
Growth factors released by oxygen-starved cells prompt nearby endothelial cells, which line blood vessels, to grow into new networks. Researchers at Rice University are working to understand how to direct the process in the brains of stroke and disease patients. (Credit: Qutub Lab/Rice University)
Images of angiogenesis captured in cell cultures at Rice University are compared with "robot" cells growing in a computer simulation. The technique allows researchers to refine their models for prompting microvasculature growth in the brain, with the ultimate goal of helping patients recover from stroke and disease. (Credit: Qutub Lab/Rice University)
Members of Rice's Qutub lab treat endothelial cells as though they were robots in their simulation of angiogenesis in the brain. From left: Byron Long, Amina Qutub, Jiwon Jung and Rahul Rekhi. (Credit: Jeff Fitlow/Rice University)
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Rice University lab shows how blood vessels regroup after strokePublic release date: 11-Feb-2013 [ | E-mail | Share ]
Contact: David Ruth david@rice.edu 713-348-6327 Rice University
By thinking of cells as programmable robots, researchers at Rice University hope to someday direct how they grow into the tiny blood vessels that feed the brain and help people regain functions lost to stroke and disease.
Rice bioengineer Amina Qutub and her colleagues simulate patterns of microvasculature cell growth and compare the results with real networks grown in their lab. Eventually, they want to develop the ability to control the way these networks develop.
The results of a long study are the focus of a new paper in the Journal of Theoretical Biology.
"We want to be able to design particular capillary structures," said Qutub, an assistant professor of bioengineering based at Rice's BioScience Research Collaborative. "In our computer model, the cells are miniature adaptive robots that respond to each other, respond to their environment and pattern into unique structures that parallel what we see in the lab."
When brain cells are deprived of oxygen a condition called hypoxia that can lead to strokes they pump out growth factor proteins that signal endothelial cells. Those cells, which line the interior of blood vessels, are prompted to branch off as capillaries in a process called angiogenesis to bring oxygen to starved neurons.
How these new vessels form networks and the shapes they take are of great interest to bioengineers who want to improve blood flow to parts of the brain by regenerating the microvasculature.
"The problem, especially as we age, is that we become less able to grow these blood vessels," Qutub said. "At the same time, we're at higher risk for strokes and neurodegenerative diseases. If we can understand how to guide the vessel structures and help them self-repair, we are a step closer to aiding treatment."
First, they need to understand how individual cells respond to stimuli. To model the process in a computer requires rules, Qutub said. In these simulations, each cell is a "state machine," a unit that goes from one "state" to the next in time based on input. In the case of these endothelial cells, the input comes from vascular endothelial growth factor and/or brain-derived neurotrophic factor, proteins that encourage angiogenesis.
"There's a memory in each of these cells that helps define how they emerge into these very elaborate vasculature structures," she said. The cells that quickly differentiate into tip and stalk cells follow particular rules to advance, grow, divide and branch, depending on input from growth factors and from neighboring cells that can dictate how far and how fast they develop.
For instance, she said, in a chain of endothelial cells, a tip cell at its maximum length can only continue to migrate if the stalk cell immediately behind grows and pushes it forward. Similarly, the team set rules for branching and changes in direction, as well as an "idle" state, all based on observation of real vessel growth.
The researchers modeled a set of endothelial cells growing from a sphere and exposed them to simulated growth factors. They let them grow for what, in real life, would be a period of 24 hours, but in the computer took fractions of a second. They ran tens of thousands of simulations to see how the cells would migrate, proliferate and branch under various conditions.
The next step was to figure out which of the computer simulations matched actual behavior. Qutub's lab cultured spheres of human umbilical vein endothelial cells in collagen scaffolds, exposed them to growth factors and took microscope images as they developed networks over several days.
They compared these images with the simulations. The closest matches of which there are only a few amid thousands of simulations became the basis for a refined set of rules.
"We know how cells are connected as a function of the growth factors, and there are very distinct patterns to the way these networks are organized," Qutub said. "So when we compare the simulations with the assays, we find parallels that let us classify what we see in the real networks. This gives us a paradigm where we can start to think of actually programming real cells with chemical signaling.
"It opens up a lot of doors," she said. "Now we can think about changing things in the cells or giving them drugs that target pathways and growth factors to induce a particular vasculature structure."
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Byron Long, a postdoctoral research associate in the Qutub Group, is lead author of the paper. Co-authors are Rice undergraduates Rahul Rekhi and Jiwon Jung and Amada Abrego, an undergraduate student at the Monterrey Institute of Technology, Mexico, who took part in the Rice Summer Undergraduate Research Program in Biosciences and Bioengineering, funded by the Howard Hughes Medical Institute, and has a complimentary appointment to the Qutub Lab.
The research was funded in part by a National Academies Keck Future Initiatives grant, a Hamill Innovation Award and a National Science Foundation CAREER award.
Read the abstract at http://dx.doi.org/10.1016/j.jtbi.2012.11.030
See a short video of simulated network growth at http://youtu.be/7Qly07KMp-s
Follow Rice News and Media Relations via Twitter @RiceUNews
Related Materials:
Qutub Systems Biology Lab: http://www.qutublab.rice.edu/index.html
Multiscale Models of Angiogenesis: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3077679/
Growth factors released by oxygen-starved cells prompt nearby endothelial cells, which line blood vessels, to grow into new networks. Researchers at Rice University are working to understand how to direct the process in the brains of stroke and disease patients. (Credit: Qutub Lab/Rice University)
Images of angiogenesis captured in cell cultures at Rice University are compared with "robot" cells growing in a computer simulation. The technique allows researchers to refine their models for prompting microvasculature growth in the brain, with the ultimate goal of helping patients recover from stroke and disease. (Credit: Qutub Lab/Rice University)
Members of Rice's Qutub lab treat endothelial cells as though they were robots in their simulation of angiogenesis in the brain. From left: Byron Long, Amina Qutub, Jiwon Jung and Rahul Rekhi. (Credit: Jeff Fitlow/Rice University)
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A look at effects in states and provinces in the path of the massive storm that swept across the Northeast U.S. and southern Canada:
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CONNECTICUT
The storm dumped at as much as 3 feet of snow on Connecticut, paralyzing much of the state. President Barack Obama declared a state of emergency for the state, allowing federal aid to be used in recovery.
Five deaths apparently were weather related, Gov. Dannel P. Malloy said, including a 73-year-old man who died when he fell while cleaning up in Danbury. The National Guard was brought in to help clear snow in New Haven, which got 34 inches. Snow totals were 32 inches in Manchester and 20 inches in Danbury.
The governor ordered all roads closed for nearly a day, and even emergency responders got stuck on highways. About 38,000 homes and businesses were without power at the storm's peak.
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MAINE
Portland set a record snowfall reading of 31.9 inches, the National Weather Service said, and blowing snow reduced visibility on the coast. The weather contributed to a fatal crash.
Vehicles, including state police cruisers, were stuck in the deep snow, state police said, warning that stranded drivers should expect long waits for tow trucks. About 12,000 homes and businesses lost power.
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MASSACHUSETTS
Boston was blanketed in up to 2 feet of snow, falling short of the city's record of 27.6 inches set in 2003. In some communities just outside the city, totals were higher, including 30 inches in both Quincy and Framingham. Hardest hit were the South Shore and Cape Cod, but there were no serious injuries due to flooding, the governor said.
An 11-year-old boy died of carbon monoxide poisoning after being overcome as he sat in a running car to keep warm, while his father was shoveling snow to get the car out of a snow bank in Boston's Dorchester neighborhood. A Boston man believed to be in his 20s also died of carbon monoxide poisoning in a running, snowed-in car. Also, a longtime member of the Worcester Fire Department suffered a heart attack after shoveling snow at his Webster home Saturday and died at a hospital.
Public transit in the city was suspended, and authorities hoped to have trains and buses running in time for Monday morning's commute. Logan Airport was closed until late Saturday.
More than 400,000 customers lost power in the state, and some were warned to expect to be without it for days. Many areas were too dangerous to send in crews, utility NStar said. Crews whittled the total down by more than 180,000 by Sunday, after about 1,000 people spent the night in emergency shelters.
The state enforced its first travel ban on roads since the Blizzard of '78, a ferocious storm that dropped 27 inches of snow, packed hurricane-force winds and claimed dozens of lives.
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NEW HAMPSHIRE
The capital of Concord saw its second-highest snow total on record, 24 inches. Both Seabrook and East Hampstead saw 26 inches of snow. There were only a few hundred power failures statewide.
Saturday morning's high tide sent waves crashing into closed roads along the seacoast, local police said, but there were no reports of significant damage.
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NEW JERSEY
The state was spared the worst of the storm, and the highest snowfalls were spread across northern New Jersey, where River Vale got 15 inches, the National Weather Service reported.
Bus and train service that was briefly suspended, and Newark Liberty Airport was closed Friday night. Flooding, seen on a massive scale during Superstorm Sandy, did not appear to cause major problems.
Officials say just a few thousand customers lost power during the storm, and nearly all had their service restored by early Saturday afternoon.
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NEW YORK
Police had to use snowmobiles to reach ambulances, fire trucks, police vehicles, some snowplow trucks and passenger vehicles stranded overnight on the Long Island Expressway. About 10,000 homes and businesses lost power on Long Island, which saw as much as 2? feet of snow.
About a foot of snow fell on New York City, which was "in great shape," Mayor Michael Bloomberg said. The Staten Island neighborhoods hit hardest by Superstorm Sandy dodged another round of flooding.
Airports reopened Saturday. Amtrak said trains between New York and Boston were suspended Saturday but some trains would run Sunday.
Three deaths in the state were blamed on the storm. A 23-year-old man plowing his driveway with a farm tractor went off the edge of the road and was killed in Columbia County, police said. A 74-year-old was fatally struck by a car in Poughkeepsie; the driver said she lost control in the snowy conditions, police said. And a 58-year-old man apparently suffered a medical problem while removing snow from his car at a senior citizens' apartment complex in Selden on Long Island.
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RHODE ISLAND
Residents were urged to stay off the roads to allow crews to clear up to 2 feet of snow. About 180,000 homes and businesses lost power, and utilities warned it could be out for days.
At T.F. Green Airport, outbound flights were to resume Sunday afternoon. Public transit service scheduled to resume Monday.
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VERMONT
Wind, not snow or tides, was the issue in Vermont. Ferry service between Charlotte, Vt., and Essex, N.Y., was closed Saturday because of the gusts. Parts of the state saw 10 inches of snow.
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Sources: State and local authorities; AP reporting
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FILE - In this Feb. 4, 2013 file photo, investigators work the scene where a tour bus collided with a pickup truck on Highway 38 north of Yucaipa, Calif., killing eight people. Federal regulators on Friday, Feb. 8, 2013 ordered the tour bus operator, National City, Calif.-based Scapadas Magicas LLC, to immediately stop operating because its buses weren't properly maintained or inspected and its drivers weren't properly vetted for qualifications. (AP Photo/Ringo H.W. Chiu, File)
FILE - In this Feb. 4, 2013 file photo, investigators work the scene where a tour bus collided with a pickup truck on Highway 38 north of Yucaipa, Calif., killing eight people. Federal regulators on Friday, Feb. 8, 2013 ordered the tour bus operator, National City, Calif.-based Scapadas Magicas LLC, to immediately stop operating because its buses weren't properly maintained or inspected and its drivers weren't properly vetted for qualifications. (AP Photo/Ringo H.W. Chiu, File)
FILE - In this Feb. 4, 2013 photo, investigators work the scene where a tour bus collided with a pickup truck on Highway 38 north of Yucaipa, Calif., killing eight people. Federal regulators on Friday, Feb. 8, 2013 ordered the tour bus operator, National City, Calif.-based Scapadas Magicas LLC, to immediately stop operating because its buses weren't properly maintained or inspected and its drivers weren't properly vetted for qualifications. (AP Photo/The Sun, Rick Sforza, File)
FILE - This Feb. 4, 2013 file photo shows Investigators working the scene of a bus crash on Highway 38 that killed at least 8 people, near Yucaipa, Calif. US regulators have ordered the immediate shutdown of this tour bus operator involved in this Southern California crash, Friday, Feb. 8, 2013. (AP Photo/The Press-Enterprise, Stan Lim) NO SALES; MAGS OUT; MANDATORY CREDIT
LOS ANGELES (AP) ? Federal regulators on Friday ordered a tour bus operator involved in a Southern California crash that killed eight people to immediately stop operating because its buses weren't properly maintained or inspected and its drivers weren't properly vetted for qualifications.
The Federal Motor Carrier Safety Administration said in a statement that it ordered all three buses operated by National City, Calif.-based Scapadas Magicas LLC in the U.S. to stop operating because they pose an imminent hazard to public safety.
The roadworthiness of the 1996 bus involved in the Feb. 3 crash has been in doubt after the driver said the brakes failed before it smashed into a sedan, flipped, slammed into a pickup and crashed on a road in the San Bernardino Mountains east of Los Angeles. The bus was carrying 38 people, including the driver and a tour guide, to Tijuana, Mexico.
Regulators said Friday that a post-crash investigation of the company's two other buses that had been operating in the U.S. found serious mechanical safety violations.
Inspectors said the company failed to have its vehicles regularly inspected before the deadly crash. When the buses were inspected, there were many violations, including multiple brake problems.
Vehicle maintenance violations were cited during 21 of Scapadas Magicas' 25 most recent vehicle inspections, and vehicles had to be placed out of service after 36 percent of the inspections, according to the order to cease operations.
In a January 2013 compliance review conducted by transportation regulators, breakdowns were identified in the company's safety management systems, but "Scapadas Magicas failed to take necessary action to remedy its safety management deficiencies," the order said.
Calls to Scapadas Magicas' offices seeking comment Friday night were unsuccessful.
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Shaya Tayefe Mohajer can be reached at http://www.twitter.com/APShaya . Associated Press writer Elliot Spagat contributed to this report from San Diego.
TUNIS (Reuters) - Thousands of Islamists marched in Tunis on Saturday in a show of strength, a day after the funeral of an assassinated secular politician drew the biggest crowds seen on the streets since Tunisia's uprising two years ago.
About 6,000 supporters of the ruling Ennahda movement rallied to back their leader Rachid al-Ghannouchi, who was the target of angry slogans raised by mourners at Friday's mass funeral of Chokri Belaid, a rights lawyer and opposition leader.
"The people want Ennahda again," the Islamists chanted, waving Tunisian and party flags as they marched towards the Interior Ministry on Habib Bourguiba Avenue in the city centre.
The demonstration was dwarfed by the tens of thousands who had turned out in Tunis and other cities to honor Belaid and to protest against the Islamist-led government the day before, shouting slogans that included "We want a new revolution".
Belaid's killing by an unidentified gunman on Wednesday, Tunisia's first such political assassination in decades, has shaken a nation still seeking stability after the overthrow of veteran strongman Zine al-Abidine Ben Ali in January 2011.
The family of the slain politician has accused Ennahda of responsibility for his killing. The party denies any hand in it.
"We are here to support legitimacy, but if you prefer the power of the street, look at the streets today, we have this power," Lotfi Zitoun, an Ennahda leader, said in a speech to the Islamist demonstrators in Tunis.
Tunisia's political transition has been more peaceful than those in other Arab nations such as Egypt, Libya and Syria, but tensions are running high between Islamists elected to power and liberals who fear the loss of hard-won liberties.
FREEDOMS THREATENED
"We have gained things - the freedom of expression, the freedom to meet, to form organizations, parties, to work in the open," said Radhi Nasraoui, a veteran human rights campaigner.
"The problem is that these freedoms are still threatened, and there are attempts (by Islamists) to touch the gains of women," she told Reuters.
After Belaid's death, Prime Minister Hamadi Jebali promised to form a non-partisan, technocratic cabinet to run the country until an election could take place, despite complaints from within his own Ennahda party and its two junior non-Islamist coalition partners that he had failed to consult them.
Jebali told France 24 television on Saturday that he would resign if political parties refused to support his proposal, which he said was intended to "save the country from chaos".
The state news agency TAP said the prime minister would unveil his new government next week.
Secular groups have accused the Islamist-led government of a lax response to attacks by ultra-orthodox Salafi Islamists on cinemas, theatres, bars and individuals in recent months.
Prolonged political uncertainty and street unrest could damage an economy that relies on tourism. Unemployment and other economic grievances fuelled the revolt against Ben Ali in 2011.
Tunisia's stock exchange has fallen 3.32 percent since Belaid's assassination.
France, the former colonial power, ordered its schools in Tunis to stay closed on Friday and Saturday, warning its nationals to stay clear of potential flashpoints in the capital.
Some of the Islamist demonstrators shouted "France, out", in response to remarks by French Interior Minister Manuel Valls which were rejected by Jebali, the prime minister, on Friday.
"We must support all those who fight to maintain values and remain aware of the dangers of despotism, of Islamism that threatened those values today through obscurantism," Valls had said on Europe 1 radio on Thursday in comments on Tunisia.
"There is an Islamic fascism which is on the rise in many places."
Tunisian Foreign Minister Rafik Abdessalem described Valls's remarks as "worrying and unfriendly".
Feb. 7, 2013 ? Albert Einstein called quantum entanglement -- two particles in different locations, even on other sides of the universe, influencing each other -- "spooky action at a distance."
Einstein made the comment while criticizing quantum mechanics as incomplete -- the phenomenon of quantum entanglement seems to be at odds with Einstein's theory of relativity.
"Eighty years after Einstein, quantum physics is still so mysterious that there are many different interpretations of its physical meaning. All the interpretations agree on what is going to be observed in any given experiment, but they each tell different stories of how these observations come about," says Christoph Simon with the Department of Physics and Astronomy in the Faculty of Science at the University of Calgary.
Simon and his colleague, Boris Braverman from the Massachusetts Institute of Technology have shown this spooky action at a distance in research published February 8 in Physical Review Letters. The paper proposes a way in which the effect can be shown experimentally.
"We consider spooky action at a distance in the framework of an interpretation from the English physicist David Bohm who posited that every quantum particle has a well-defined position and velocity," says Simon.
"If the two particles are entangled, then performing an action on one has an immediate effect on the other and our paper shows how this effect can be demonstrated in an experiment with entangled photons."
Entangled photons present an exciting new method of secure communications -- it's impossible for people to listen in. But this phenomenon can't be used for communication faster than the speed of light (what physicists call superluminal), allowing quantum physical systems to obey Einstein's theory of relativity, which posits that things can't communicate faster than light.
There is either no explanation for this -- it's magic and somehow there are the same outcomes on each side -- or the communication between photons is superluminal, which is problematic given the theory of relativity. "There has to be a way out," says Simon.
"Different pairs of particles coming from the same source have slightly different positions and velocities," he says. "If you observe just one of the two particles from a pair, you can't be sure if a variation in its velocity, say, is due to the long-distance influence of its partner, or whether it is just a statistical fluctuation. In this way the peaceful coexistence of quantum physics and relativity is preserved."
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The above story is reprinted from materials provided by University of Calgary, via EurekAlert!, a service of AAAS.
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Journal Reference:
Boris Braverman, and Christoph Simon. Proposal to Observe the Nonlocality of Bohmian Trajectories with Entangled Photons. Physical Review Letters, 2013 DOI: 10.1103/PhysRevLett.110.060406
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It is Valentine?s Day and I want to talk to you about how you smell. This will not be a discussion about how your musky, earthy scent attracts a mate. No, we need to have a conversation about how your urinous, acidic odor might drive one away.
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Public release date: 11-Feb-2013
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