University of Virginia history professor Philip Zelikow has taught the course, "The Modern World: Global History Since 1760" for 16 years -- but this semester is different. Instead of delivering it to 120 students on campus, he'll be teaching 42,000 students around the world.

While online learning is not new, access to top-notch professors at some of the world's most prestigious universities is. Along with the University of Virginia, Harvard University, Stanford University, Brown University, Johns Hopkins University, Princeton University, the Massachusetts Institute of Technology and Columbia University are among dozens of elite institutions partnering with start-up companies such as Coursera, Udacity and edX, to deliver so-called massive open online courses or MOOCs.

Now, Greek history at Wesleyan University, poetry at the University of Pennsylvania, astronomy at Duke University, and "Introduction to Music Production" at the Berkley College of Music are all just a click away. And they're absolutely free.

Since 2011, more than 2.5 million students from around the world have enrolled in MOOCs. Even though they are not offered for college credit and completion rates are low, some educators see the potential to revolutionize higher learning.

"Thanks to these free online courses, you can shop a range of disciplines and do it all from the comfort at your own home," Coursera co-founder Daphne Koller said.

Zelikow was apprehensive at first. 

"I'm not a techie guy who's interested in experimenting with all this computer stuff," he said. "In fact, I was kind of a skeptic about all this online stuff. I thought it was fad-ish."

But after spending hundreds of hours preparing for this semester's course, Zelikow now sees the potential in expanding online.

"Bruce Springsteen is involved in selling recorded music to people all over the world. And he also sells tickets to live concerts," Zelikow said. "Nobody thinks the recorded music is just as good as the live concert. But he wants to be in both those lines of business."

He says there's not only value in reaching thousands of students worldwide, but believes the move online has actually improved his course for those taking it on campus.

"I thought of ways to use this [online course] to actually re-invent the ways I teach my ordinary class at the university and make it a better class than it used to be, to solve certain problems that are kind of structural problems in the way we teach our residential courses," Zelikow said.

Dawn Smith, 38, has taken "Fundamentals of Pharmacology" through the University of Pennsylvania and a public health class through Johns Hopkins after deciding to change careers.  

"I needed some textbook knowledge," Smith said. "I felt in order to be taken seriously as a candidate I needed to show I was doing something proactive."

Critics of MOOCs complain about their size, saying it leads to minimal student-professor interaction.

"I've met students from Germany that I've spoken to quite frequently - Australia, Japan, China, and then some in Africa," Smith said.

Although she would "absolutely recommend" this online platform, Smith acknowledges the limitations, too.

"There isn't that immediacy of being able to ask a question and then have an answer," Smith said. "There's no one standing in front of you showing you how to do something."

Other concerns include measuring student progress and the sustainability of these courses over a long period of time.

Siva Vaidyanathan, University of Virginia media studies professor, says he thinks MOOCs are an "interesting experiment," but that they're just that - an experiment.

He doesn't believe they can replace a traditional college education.

"Imagine taking a university and removing all the really fun stuff," Vaidyanathan said. "And all you're left with is me talking to you through a camera. That's not that good for anybody."

As professors, students and investors navigate this new terrain, there are questions about the potential for profit in the future and the place MOOCs may have in higher education.

For some, however, these online classes bring about hope.

"Education is such an equalizer. It raises people's abilities … lets people build a better life," Coursera co-founder Andrew Ng said.

Even Vaidyanathan sees the silver lining.

"I hope somewhere in some corner of the world … some child discovers calculus, discovers physics, or discovers poetry through a MOOC and gets … inspired to change the world," he said.  

In our report below - on cats and birds - we stated that the study was conducted by the  U.S. Fish and Wildlife Service. To clarify, it was a joint study with The Smithsonian Conservation Biology Institute.

Monday on 'NBC Nightly News,' Kerry Sanders profiled the daughter of migrant farm workers, Estella Pyfrom, who is now providing underserved children with access to technology aboard her 'Brilliant Bus.' It's a project she bankrolled herself after working for decades as a teacher and observing the 'digital divide' first-hand.  

Click here to visit the Brilliant Bus website and learn more about Pyfrom's organization. 

The Boy Scouts of America, one of the nation’s largest private youth organizations, is actively considering an end to its decades-long policy of banning gay scouts or scout leaders, according to scouting officials and outsiders familiar with internal discussions.

If adopted by the organization’s board of directors, it would represent a profound change on an issue that has been highly controversial -- one that even went to the US Supreme Court. The new policy, now under discussion, would eliminate the ban from the national organization’s rules, leaving local sponsoring organizations free to decide for themselves whether to admit gay scouts.

“The chartered organizations that oversee and deliver scouting would accept membership and select leaders consistent with their organization’s mission, principles or religious beliefs,” according to Deron Smith, a spokesman for the Boy Scouts’ national organization.

Individual sponsors and parents “would be able to choose a local unit which best meets the needs of their families,” Smith said.

The discussion of a potential change in policy is nearing its final stages, according to outside scouting supporters. If approved, the change could be announced as early as next week, after the BSA's national board holds a regularly scheduled meeting.

Only seven months ago, the Boy Scouts affirmed a policy of banning gay members, after a nearly two-year examination of the issue by a committee of volunteers convened by national leaders of the Boy Scouts of America, known as the BSA.

In a statement last July affirming the ban, its national executive board called it “the best policy for the organization.”

But since then, a scouting official said, local chapters have been urging a reconsideration. "We're a grassroots organization. This is a response to what's happening at the local level," the official said.

Two corporate CEOs on BSA’s national board, Randall Stephenson of AT&T and James Turley of Ernst & Young, have also said they would work to end the ban. Stephenson is next in line to be the BSA’s national chairman. During the 2012 presidential campaign, both Barack Obama and Mitt Romney said the BSA should admit gay scouts and scout leaders.

About 50 local United Way groups and several corporations and charities have concluded that the ban violates their non-discrimination requirements and have ceased providing financial aid to the Boy Scouts. An official of The Human Rights Campaign, an advocate for gay rights, said HRC planned to downgrade its non-discrimination ratings for corporations that continue to give the BSA financial support.

“It’s an extremely complex issue,” said one Boy Scouts of America official, who explained that other organizations have threatened to withdraw their financial support if the BSA drops the ban.

While the national scouting organization sets broad policies, more than 290 local councils nationwide govern the day-to-day conduct of the more than 116,000 local organizations. Individual scouting troops are sponsored by religious and civic organizations that represent a diversity of views on the issue of allowing gay scouts and leaders.

“The beliefs of the sponsoring organizations are highly diverse,” the official said.

The policy change now under discussion “would allow the religious, civic or educational organizations that oversee and deliver Scouting to determine how to address this issue,” said the BSA's Smith.

“The Boy Scouts would not, under any circumstances, dictate a position to units, members or parents. Under this proposed policy, the BSA would not require any chartered organization to act in ways inconsistent with that organization’s mission, principles or religious beliefs,” he said.

In 2000, the U.S. Supreme Court concluded that the Boy Scouts had a First Amendment right of free expression when it came to the organization’s belief that homosexual conduct is inconsistent with values stated in the scout oath, requiring scouts to be “morally straight.”

The Scouts have won similar legal battles, with courts finding that the BSA’s right of free association permits it, as a private organization, to reject those it believes do not conform to is values. 

Related: 
Eagle Scouts return badges to protest policy banning gays 
Gay mom upset after dismissal by Boy Scouts 

Handing a huge legal victory to Republicans, a federal appeals court in Washington has ruled that a president can make recess appointments only during a congressional recess when the vacancies arise.

The ruling came Friday from a three-judge panel of the US Court of Appeals for the District of Columbia.  Business groups challenged last year's recess appointments to the NLRB, the National Labor Relations Board, and the court ruled today in their favor.

"The filling up of a vacancy that happens during a recess must be done during the same recess in which the vacancy arose," the court said.

Last January, President Barack Obama infuriated Senate Republicans by naming Richard Cordray to be director of the newly formed Consumer Financial Protection Bureau, and by putting three new members on the NLRB. (Obama re-nominated Cordray to a full appointment at the same position on Thursday.)

"It's clear the president would rather trample our system of separation of powers than work with Republicans to move the country forward," House Speaker John Boehner said at the time.  "I expect the courts will find the appointment to be illegitimate."

The court ruled today on a challenge to the appointments brought by a Pacific Northwest soft drink bottler who lost a union dispute before the NLRB. The company claimed that the president had no power to appoint the new NLRB members, and that the subsequent action by the board therefore lacked legitimacy.

At the core of the dispute is Article II of the Constitution, setting out the president's duties and authorities. They include "the power to fill up all vacancies that may happen during the recess of the Senate."

During the nation's first century, Congress was in session less than half a year. The recess appointment power allowed the president to keep the government functioning by filling important jobs when the Senate was not around to act on nominations.

"There is no reason the Framers would have permitted the President to wait until some future intersession recess to make a recess appointment, for the Senate would have been sitting in session during the intervening period and available to consider nominations," the court said today.

In modern times, presidents of both parties have used the power to make appointments during much shorter congressional recesses in the summer and around holidays. 

But during the George H.W. Bush administration, Democrats came up with the idea of pro forma sessions, in which the body was gaveled to order then immediately adjourned for another few days. They claimed that the Senate remained in session and recess appointments could not be made. Senate Republicans have since continued the pro forma practice. 

"Such short intra-session breaks are not recesses," the bottling company argued.  "Otherwise, every weekend, night, or lunch break would be a 'recess' too."

Senate Republicans joined the lawsuit. They argued that by declaring the Senate incapable of performing its functions during the pro-forma sessions, "the President usurped the Senate's control of its own procedures. And by appointing officers without the Senate's consent, he took away its right to review and reject his nominations."

The Obama Justice Department argued that the pro-forma procedures, each lasting less than a minute, are a sham and do not mean the Senate was actually in session.  "It could not provide advice or consent on presidential nominations during that 20-day period," government lawyers argue.

In agreeing to its holiday break, Justice Department lawyers note, the Senate "provided by order that 'no business' would be conducted."

The government lawyers said there's nothing mysterious about the meaning of the word recess -- "a break by the Senate from its usual business, such as periods in which the Framers anticipated that senators would return to their respective states."
 
"The pro forma sessions were not designed to permit the Senate to do business, but rather to ensure that no business was done," the Justice Department claimed.

President Obama invoked the recess appointment power 32 times during his first term to fill vacancies in full-time government positions, though he has not made any since last January's controversy. President Clinton made 95 recess appointments during his administration.  President George W. Bush used the power 99 times. 

If, as seems likely, the issue gets to the Supreme Court, the justices could settle a passionate debate over a presidential power used hundreds of times, stirring controversy since the beginning.

Updated at 2:20p.m. ET: President Barack Obama’s choice to be secretary of state, Sen. John Kerry, D- Mass, testified Thursday before the Senate Foreign Relations Committee, one day after the same committee conducted a fractious hearing with current Secretary of State Hillary Clinton over last September's attack on the U.S. diplomatic mission in Benghazi, Libya.

Unlike Wednesday’s sometimes-contentious hearings, Republicans welcomed Kerry, who is currently the chairman of the same committee, warmly at the outset.

Sen. John McCain R-Ariz. joined Clinton and Sen. Elizabeth Warren D-Mass. in introducing the nominee, with McCain praising him for “exemplary statesmanship” in his work on an accord to allow opening of normal diplomatic relations with Vietnam in 1995.

But while the hearing remained cordial, Kerry came under bipartisan pressure on the question of the civil war in Syria in which more than 60,000 have been killed.

Kerry has met several times over the years with Syrian leader Bashar al-Assad.

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McCain, part of a bipartisan group of senators which just got back from a trip to the Mideast and visited camps where Syrian refugees are living, told Kerry they feel “an anger and frustration” and believe that the United States is indifferent to their suffering.

One Syrian teacher told McCain and the other senators, “This next generation of children will take revenge on those that that did not help them.” McCain added, “We are sowing the wind in Syria and we are going to reap the whirlwind.”

He said “We can do a lot more, without putting boots on the ground” – such as a no-fly zone – and he complained that “all I get, frankly, from the (Obama) administration is the fall of Assad is, quote, ‘inevitable.’ I agree, but what about what happens in the meantime?”

Another member of the delegation that toured the Middle East, Sen. Chris Coons, D- Del., complained to Kerry that U.S. humanitarian aid intended for Syrian refugees “has not reached the people on the ground.”

In response to both Coons and McCain, Kerry said “if you have a complete implosion of the state” in Syria after Assad’s fall, it would greatly increase the risk that Assad’s chemical weapons arsenal would fall into the wrong hands.

Kerry also said that “we need to change Bashar Assad’s calculation. Right now President Assad doesn’t think he’s losing -- and the opposition thinks it is winning.” Kerry said the goal of U.S. policy is a peaceful transition to a new government. He said he hoped to confer with the Russian government, a major supporter of Assad, and with others and “increase the readiness of President Assad to see that the die is cast, the handwriting is on the wall….”

Coons told Kerry, “We frankly face a very narrow window to make a difference on the ground in support of the opposition.”  

“I get it,” Kerry answered, saying he did not want to “wind up with them (members of the anti-Saddam Syrian opposition) blaming you” for not doing more to remove Assad from power. But Kerry voiced worry about who would control the country if Assad were forced out of power.

Saul Loeb / AFP - Getty Images

Senator John Kerry, D-Mass., President Barack Obama's nominee for Secretary of State, speaks with Sen. John McCain, R-Ariz., before he testifies at the Senate Foreign Relations committee during his confirmation hearing on Capitol Hill in Washington, DC, on Jan. 24, 2013.

The committee’s ranking Republican, Sen. Bob Corker of Tennessee, asked Kerry about Obama’s nominee to be defense secretary, former Sen. Chuck Hagel and his support for Global Zero, a group which calls for the total abolition of nuclear weapons.

Kerry said Hagel would be “a strong secretary of defense secretary” and that Hagel would not weaken the U.S. nuclear arsenal which serves as a deterrent to an attack on the United States.

A world without any nuclear weapons, Kerry said, was a goal “worth aspiring to,” but “we’re not talking about today’s world” and it might take “many centuries” to achieve abolition of nuclear weapons.

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Kerry also addressed Iran's nuclear program.

“The president has made it definitive--we will do what we must to prevent Iran from obtaining a nuclear weapon,” he said in his opening statement to the committee. “I repeat here today: our policy is not containment. It is prevention and the clock is ticking on our efforts to secure responsible compliance.”

He added, “No one should mistake our resolve to reduce the nuclear threat.”

He said Obama “knows that American foreign policy is not defined by drones and deployments alone. We cannot allow the extraordinary good we do to save and change lives to be eclipsed entirely by the role we have had to play since September 11th, a role that was thrust upon us.”

Referring to the impasse over reducing budget deficits and the growing national debt, Kerry said to the committee members that “the first priority of business which will affect my credibility as a diplomat – and our credibility as nation – as we work to help other countries create order, is whether America at last puts its own fiscal house in order.”

In his opening statement, Kerry showed one brief moment of emotion. His voice shook when he referred to his father, who was a Foreign Service officer. Kerry said he was proud that “the Senate is in my blood – but equally proud that so too is the Foreign Service. My father’s work under presidents both Democrat and Republican took me and my siblings around the world for a personal journey that brought home the sacrifices” that American diplomats abroad make or their country.

Updated at 2:20p.m. ET: In a hearing marked by sometimes sharp and pointed exchanges, Secretary of State Hillary Clinton told the Senate Foreign Relations Committee she took responsibility for not adequately protecting U.S. personnel in the Sept. 11 attack on a diplomatic facility in Benghazi, Libya that resulted in the killing of Ambassador Chris Stevens and three other Americans. 

Defending the administration’s immediate handling of the attack, Clinton clashed at times with Republicans over the account the administration gave in the initial days after Sept. 11.

Clinton said the Obama administration did not try to mislead the American people about the cause of the attacks. “Nothing could be further from the truth,” she said as she sparred with Sen. Ron Johnson, R- Wisc.

She angrily told Johnson that at this stage it did not really matter what the precise origins or motives of the attack were: “What difference at this point does it make?”

She told Arizona Sen. Jeff Flake, a Republican, “we did not have a clear picture” of all that was going on in Benghazi although she did acknowledge that senators had “legitimate questions” about the administration’s account.

Sen. John McCain, R- Ariz., -- after telling Clinton “we are proud of you” and that all over the world “you are viewed with admiration and respect” -- delivered a blistering criticism of the Obama administration’s handling of the events in Libya.

“There are many questions that are unanswered and the answers you’ve given this morning are frankly not satisfactory to me,” McCain told Clinton. He added “the American people and the families of these four brave Americans still haven’t gotten the answers they deserve.”

He asked Clinton whether she was aware of numerous warnings from Stevens and other Americans in Libya that the facility in Benghazi was not capable of resisting a sustained assault. He also said there had been other warning signs such as an attack on the British ambassador to Libya.

He angrily asked Clinton why Defense Department forces were not nearby to defend the Benghazi facility.

Last month a report issued by the Accountability Review Board (ARB) appointed by Clinton, blamed State Department officials for “systemic failures and leadership and management deficiencies” that led to protection for the Benghazi facility that was “grossly inadequate to deal with the attack that took place.”

In her response to McCain, Clinton said, as she did to other senators on the panel, that some additional information on the causes and circumstances of the attack is in the classified portions of the report issued by the ARB. Senators and Senate staff can read the classified portions of the ARB report, but the public cannot.

And she blamed members of Congress for holding up additional aid to Libya that might make the country more secure and less chaotic. 

Clinton was testifying Wednesday afternoon on Benghazi before the House Foreign Affairs Committee.

In his questioning of Clinton Wednesday morning, Sen. Rand Paul, R- Ky., told her, “I’m glad that you’re accepting responsibility. I think that ultimately with your leaving, you accept the culpability for the worst tragedy since 9/11, and I really mean that. Had I been president at the time and I found that you did not read the cables from Benghazi, you did not read the cables from Ambassador Stevens, I would have relieved you of your post.”

He added, “It’s a failure of leadership” which cost the Americans in Benghazi their lives. “I think it’s good that you’re accepting responsibility-- because no one else is.”

Paul also argued that U.S. personnel ought to never have been sent to Benghazi “in a war zone” without a military guard. “You shouldn’t send them in with the same kind of embassy staff that you have in Paris,” he added. 

Clinton replied that all four State Department officials criticized in the ARB report for their roles on the Benghazi events had been removed from their jobs and placed on administrative leave. “The ARB (report) made very clear that the level of responsibility for the failures that they outlined was set at the assistant secretary level and below.”

The furor over the Benghazi attack helped derail one possible nominee to replace Clinton at the State Department, UN ambassador Susan Rice, whom Republicans assailed for using administration talking points that portrayed the incident as a spontaneous response to an inflammatory anti-Islamic video.

But Clinton told the committee that in the hours and days after the attack, “I was not focused on talking points” and “I wasn’t involved in the talking points process.”

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In her opening statement, Clinton told the committee, “As I have said many times since September 11, I take responsibility.  Nobody is more committed to getting this right.  I am determined to leave the State Department and our country safer, stronger, and more secure.”

Clinton's voice choked with emotion as she recalled the return of “those flag-draped caskets” from the Americans killed in Benghazi and put her arms “around the mothers and fathers, sisters and brothers, sons and daughters” of those killed. 

Clinton also used her testimony to deliver a vigorous call for continued U.S. involvement in the North African nation of Mali where the Obama administration is aiding French efforts to defeat Islamic jihadist forces.

She told the committee that the United States cannot allow Mali to become a safe haven for the group Al Qaida in the Islamic Maghreb (AQIM), warning of the risk of AQIM attacks on the United States itself.

Clinton also said she could not confirm reports that some of the terrorists involved in last week’s Algeria hostage taking were also involved in the Benghazi attack but called it a "new thread" to follow.

She did say that there is no doubt that Algerian terrorists have weapons they obtained from depots in Libya that were opened up and “liberated” after the dictator Moammar Gadhafi was toppled, with U.S. and NATO help, in 2011.

Gary Cameron / Reuters, file

Secretary of State Hillary Clinton speaks about the hostage situation in Algeria during a joint news conference with Japan's Foreign Minister Fumio Kishida (not pictured) after their meeting at the State Department in Washington Jan. 18, 2013.

Clinton said she had accepted the ARBs recommendations for improvements in security procedures and had asked her subordinates “to ensure that all 29 of them are implemented quickly and completely.” She said these changes are designed to “reduce the chances of another Benghazi happening again.”

On Thursday the Senate Foreign Relations Committee will hold its confirmation hearing for Clinton’s successor, Sen. John Kerry of Massachusetts, who is the committee’s chairman and is likely to be confirmed without any opposition.

Like anyone else who is getting a little older, former NFL player Wayne Clark sometimes forgets someone’s name. But unlike most people, Clark has an extra reason to worry -- as a retired  football player, he’s had more than his fair share of knocks and is now nervously watching report after report linking concussions with a brain condition known as chronic traumatic encephalopathy (CTE).

“Recalling names, which I recall used to be pretty easy for me, and now I go through stages where I think ‘Why can’t I remember that’?  I always wondered are these age-related or are they concussion-related?” Clark, 65, says.

A new study using brain scans might be able to answer that question. The technique may allow scientists to peer into the brains of the living and spot signs of the abnormally tangled clumps of a protein called "tau" that can cause such symptoms as memory loss, impulse control, mood volatility and, eventually, dementia in people with CTE.

Researchers from the University of California, Los Angeles, used the new technique to scan the brains of five former NFL players 45 and older, along with five healthy men of the same age, according to a preliminary report published Tuesday in the American Journal of Geriatric Psychiatry.

The hope is that studies like this will enable scientists to better understand CTE, says Dr. Gary Small, director of the UCLA Longevity Center, who led the study.

“Then maybe we will be able to detect it sooner and possibly come up with a preventive treatment rather than trying to repair what is damaged,” Small says.

A study of five people doesn’t say much about what might be found in a larger population. But Small and his colleagues are encouraged by what they've seen.

Each of the football players in the study had a history of one or more diagnosed concussions and several had cognitive and/or mood symptoms. The players represented a wide range of positions: linebacker, quarterback, guard, center, and defensive lineman.

At the outset, the players were asked to fill out questionnaires designed to detect signs of cognitive decline and mood symptoms.

To look for signs of CTE, Small and his colleagues injected each study volunteer with a newly developed radio tracer that locks on to the tau protein and shows up in bright colors ranging from red to yellow on PET scans.

The scans from the healthy non-players showed no signs of tau build-up, but the images from the players showed a range that correlated with the number of hits they’d sustained during their football careers.

UCLA

Brain scans of living former NFL players show evidence of the damage linked to a brain-destroying condition called CTE, researchers said on Tuesday.

Though the researchers had asked 19 players initially to participate in the study, only five were willing, Small says. And only one was willing to have his name released to the public. That was Clark, a former quarterback for the San Diego Chargers.

Clark, who had sustained only one concussion while playing football, didn’t have much evidence of tau build-up. But he did have some.

“And when I first saw the scan I thought, whoa, that looks pretty extensive,” Clark says in an video interview on UCLA's website.

“Wayne’s scans show the abnormal protein deposits, just like the other football players in the study,” Small says. “Now he's in his mid-60s and he has very minor memory complaints, which could be part of normal aging, but they also could be related to his concussion. When we do further studies, we’ll be able to find out if there’s a solid connection between the two.”

Clark hopes the research will help doctors eventually identify which players might be at risk of developing permanent brain damage. “My hope is that this study will help diagnose the condition before a player dies and is autopsied,” Clark says. "If we can diagnose it when a player is alive, then we can learn how best to intervene and how to improve equipment and rules and practice habits to we can make the game safer.”

It’s not just NFL players. Brain injuries are common among war veterans, victims of accidents and younger athletes.

The researchers don’t completely understand the relationship between tau deposits and jolts to the head. Clark’s scan suggests that one hit might possibly lead to some accumulation of the abnormal protein -- just not enough to lead to symptoms.

“We don’t know how many hits it takes,” says Dr. Joseph Maroon, a professor of neurosurgery at the University of Pittsburgh Medical Center, and team neurosurgeon for the Pittsburgh Steelers. He was not involved in this study. “We don’t know if one severe hit can lead to this progression. Some players can get thousands of hits and never develop CTE. There are millions of football players in high school, college, and pro level who have taken multiple blows to the head and not developed CTE.”

Another unresolved question is whether multiple “sub-concussive” hits, such as those sustained by linemen on every play, can lead to CTE.

Perhaps the biggest question scientists hope to solve with this type of research is what percentage of concussed players end up with CTE.

Many believe that there is a genetic component that can make a person more susceptible and that those with resilient genetics can take a number of jolts to the brain without developing the disease.

Though most of the former NFL players’ brains autopsied up to this point have shown signs of CTE, those brains have come from players who tended to have pronounced symptoms of the disease before their deaths.

Two years ago when former football star Dave Duerson committed suicide, he left a note explaining that he’d decided to shoot himself in the chest, rather than the head, so scientists might examine his brain to see if the concussions he’d suffered in his 11-year NFL career as a hard-hitting safety for the Chicago Bears, the New York Giants and the Phoenix Cardinals could explain the symptoms that were making his life a misery.

Thus far, Boston University’s Center for the Study of Traumatic Encephalopathy has found evidence of CTE in the autopsied brains of 33 former NFL players, including that of Duerson, according to a report published in December in an early online version of the journal Brain.

Some hope that the new research is just the beginning.

“This is a step forward and it emphasizes the importance of what PET scanning might hold as we go forward in trying to diagnose the condition [in living players],” says Maroon.

Maroon and others say they believe that CTE is the result of a normal inflammatory response to brain injury that runs amok. The theory is that the inflammation switch gets turned on and stays on in people with a certain genetic predisposition, Maroon says.

“One might conjecture that it’s like starting a small brush fire in a dry forest,” Maroon said. “If the predisposition is there and the fire is lit, then it may continue inexorably.”

Maroon hopes that new radio tracers will be found that highlight the early signs of inflammation before tau has even begun to accumulate. Then there might be a chance to find therapies that stop CTE from developing, he says. 

See more NBC Health news: 

• Contact sports leave pattern of brain injuries, study finds
• US launches study into youth sports concussions

In just 10 years the number of children diagnosed with attention deficit/hyperactivity disorder, or ADHD, rose dramatically, a  large new study suggests.

Overall, about 5 percent of nearly 843,000 kids ages 5 to 11 were diagnosed between 2001 and 2010 with the condition that can cause impulsive behavior and trouble concentrating. But during that time, rates of new ADHD diagnoses skyrocketed 24 percent – jumping from 2.5 percent in 2001 to 3.1 percent in 2010.

That’s according to a comprehensive review of medical records for children who were covered by the Kaiser Permanente Southern California health plan.  Rates rose most among minority kids during the study period, climbing nearly 70 percent overall in black children, and 60 percent among Hispanic youngsters, according the study published in JAMA Pediatrics. Among black girls, ADHD rates jumped 90 percent.

Rates remained highest in white children, climbing from 4.7 percent to 5.6 percent during the study period.

The biggest factor driving this increase may be the heightened awareness of ADHD among parents, teachers, and pediatricians, says the study’s lead author Dr. Darios Getahun, a scientist with Kaiser Permanente. For kids who need help, that’s a good thing, Getahun says.

“The earlier a diagnosis is made, the earlier we can initiate treatment which leads to a better outcome for the child,” he says.

Unlike previous studies in which researchers relied on reports from parents and teachers to say whether a child had ADHD, the new study tracked kids who were diagnosed according to ADHD medical codes entered by child and adolescent psychiatrists, developmental and behavioral pediatricians, child psychologists and neurologists.

ADHD is one of the most commonly diagnosed childhood disorders. Experts estimate that anywhere from 4 percent to 12 percent of school-age children are affected, many of whom continue to suffer from the disorder into adulthood.

Rates of diagnosis in the new study were greater in families with higher incomes, with nearly three-quarters of kids with ADHD coming from families that earned more than $50,000 a year.

“Higher rates of ADHD observed in affluent, white families likely represent an effort by these highly educated parents to seek help for their children who may not be fulfilling their expectations for schoolwork,” Getahun and his co-workers write.

Boys still outnumber girls 3 to 1 in ADHD diagnoses, but the gap appears to be closing among black girls.

“The increasing rate of ADHD among girls is an interesting finding and could represent an effort by parents to get more help for their daughters,” the authors say.

There was no change in the rate among Asian kids, but Getahun suspects this may have something to do with culture. Asians, as a rule, have been less likely to use mental health services and are more likely to discontinue therapy despite having equal access to care, Getahun says.

A child development specialist unaffiliated with the new study says he suspects that increased awareness of ADHD may have contributed to the increasing rate of diagnosis.

“Heightened professional awareness in general and improved efforts to detect ADHD exert an influence, but we cannot tell the magnitude of that,” says Alan Kazdin, the John M. Musser Professor of Psychology and Child Psychiatry at Yale University.

With all the coverage of the condition in the media, parents and teachers now have a better sense of what signs to look for, Kazdin says.

“Heightened awareness in the media, by parents and by teachers, too, may play a role. A child who in previous years just was said not to be able to control himself might now be more finely described.”

Related stories: 

• Childhood ADHD may limit adult achievements
• ADHD overdiagnosed in youngest kids in class
• Number of women on ADHD meds soars

Vice President Biden, Mr. Chief Justice, Members of the United States Congress, distinguished guests, and fellow citizens: 

Each time we gather to inaugurate a president, we bear witness to the enduring strength of our Constitution.  We affirm the promise of our democracy.  We recall that what binds this nation together is not the colors of our skin or the tenets of our faith or the origins of our names.  What makes us exceptional - what makes us American - is our allegiance to an idea, articulated in a declaration made more than two centuries ago:

"We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable rights, that among these are Life, Liberty, and the pursuit of Happiness." 

Today we continue a never-ending journey, to bridge the meaning of those words with the realities of our time.  For history tells us that while these truths may be self-evident, they have never been self-executing; that while freedom is a gift from God, it must be secured by His people here on Earth.  The patriots of 1776 did not fight to replace the tyranny of a king with the privileges of a few or the rule of a mob.  They gave to us a Republic, a government of, and by, and for the people, entrusting each generation to keep safe our founding creed. 

For more than two hundred years, we have. 

Through blood drawn by lash and blood drawn by sword, we learned that no union founded on the principles of liberty and equality could survive half-slave and half-free.  We made ourselves anew, and vowed to move forward together. 

Together, we determined that a modern economy requires railroads and highways to speed travel and commerce; schools and colleges to train our workers.

Together, we discovered that a free market only thrives when there are rules to ensure competition and fair play. 

Together, we resolved that a great nation must care for the vulnerable, and protect its people from life's worst hazards and misfortune.

Through it all, we have never relinquished our skepticism of central authority, nor have we succumbed to the fiction that all society's ills can be cured through government alone.  Our celebration of initiative and enterprise; our insistence on hard work and personal responsibility, are constants in our character.

But we have always understood that when times change, so must we; that fidelity to our founding principles requires new responses to new challenges; that preserving our individual freedoms ultimately requires collective action.  For the American people can no more meet the demands of today's world by acting alone than American soldiers could have met the forces of fascism or communism with muskets and militias.  No single person can train all the math and science teachers we'll need to equip our children for the future, or build the roads and networks and research labs that will bring new jobs and businesses to our shores.  Now, more than ever, we must do these things together, as one nation, and one people. 

This generation of Americans has been tested by crises that steeled our resolve and proved our resilience.  A decade of war is now ending.  An economic recovery has begun.  America's possibilities are limitless, for we possess all the qualities that this world without boundaries demands:  youth and drive; diversity and openness; an endless capacity for risk and a gift for reinvention.   My fellow Americans, we are made for this moment, and we will seize it - so long as we seize it together. 

For we, the people, understand that our country cannot succeed when a shrinking few do very well and a growing many barely make it.  We believe that America's prosperity must rest upon the broad shoulders of a rising middle class.  We know that America thrives when every person can find independence and pride in their work; when the wages of honest labor liberate families from the brink of hardship.  We are true to our creed when a little girl born into the bleakest poverty knows that she has the same chance to succeed as anybody else, because she is an American, she is free, and she is equal, not just in the eyes of God but also in our own. 

We understand that outworn programs are inadequate to the needs of our time.  We must harness new ideas and technology to remake our government, revamp our tax code, reform our schools, and empower our citizens with the skills they need to work harder, learn more, and reach higher.  But while the means will change, our purpose endures:  a nation that rewards the effort and determination of every single American.  That is what this moment requires.  That is what will give real meaning to our creed.  

We, the people, still believe that every citizen deserves a basic measure of security and dignity.  We must make the hard choices to reduce the cost of health care and the size of our deficit.  But we reject the belief that America must choose between caring for the generation that built this country and investing in the generation that will build its future.  For we remember the lessons of our past, when twilight years were spent in poverty, and parents of a child with a disability had nowhere to turn.  We do not believe that in this country, freedom is reserved for the lucky, or happiness for the few.  We recognize that no matter how responsibly we live our lives, any one of us, at any time, may face a job loss, or a sudden illness, or a home swept away in a terrible storm. The commitments we make to each other - through Medicare, and Medicaid, and Social Security - these things do not sap our initiative; they strengthen us.  They do not make us a nation of takers; they free us to take the risks that make this country great. 

We, the people, still believe that our obligations as Americans are not just to ourselves, but to all posterity.  We will respond to the threat of climate change, knowing that the failure to do so would betray our children and future generations.  Some may still deny the overwhelming judgment of science, but none can avoid the devastating impact of raging fires, and crippling drought, and more powerful storms.  The path towards sustainable energy sources will be long and sometimes difficult.  But America cannot resist this transition; we must lead it.  We cannot cede to other nations the technology that will power new jobs and new industries - we must claim its promise.  That is how we will maintain our economic vitality and our national treasure - our forests and waterways; our croplands and snowcapped peaks.  That is how we will preserve our planet, commanded to our care by God.  That's what will lend meaning to the creed our fathers once declared.

We, the people, still believe that enduring security and lasting peace do not require perpetual war.  Our brave men and women in uniform, tempered by the flames of battle, are unmatched in skill and courage.  Our citizens, seared by the memory of those we have lost, know too well the price that is paid for liberty.  The knowledge of their sacrifice will keep us forever vigilant against those who would do us harm.  But we are also heirs to those who won the peace and not just the war, who turned sworn enemies into the surest of friends, and we must carry those lessons into this time as well.

We will defend our people and uphold our values through strength of arms and rule of law.  We will show the courage to try and resolve our differences with other nations peacefully - not because we are naïve about the dangers we face, but because engagement can more durably lift suspicion and fear.  America will remain the anchor of strong alliances in every corner of the globe; and we will renew those institutions that extend our capacity to manage crisis abroad, for no one has a greater stake in a peaceful world than its most powerful nation.  We will support democracy from Asia to Africa; from the Americas to the Middle East, because our interests and our conscience compel us to act on behalf of those who long for freedom.  And we must be a source of hope to the poor, the sick, the marginalized, the victims of prejudice - not out of mere charity, but because peace in our time requires the constant advance of those principles that our common creed describes:  tolerance and opportunity; human dignity and justice. 

We, the people, declare today that the most evident of truths - that all of us are created equal - is the star that guides us still; just as it guided our forebears through Seneca Falls, and Selma, and Stonewall; just as it guided all those men and women, sung and unsung, who left footprints along this great Mall, to hear a preacher say that we cannot walk alone; to hear a King proclaim that our individual freedom is inextricably bound to the freedom of every soul on Earth. 

It is now our generation's task to carry on what those pioneers began.  For our journey is not complete until our wives, our mothers, and daughters can earn a living equal to their efforts.  Our journey is not complete until our gay brothers and sisters are treated like anyone else under the law - for if we are truly created equal, then surely the love we commit to one another must be equal as well.  Our journey is not complete until no citizen is forced to wait for hours to exercise the right to vote.  Our journey is not complete until we find a better way to welcome the striving, hopeful immigrants who still see America as a land of opportunity; until bright young students and engineers are enlisted in our workforce rather than expelled from our country.  Our journey is not complete until all our children, from the streets of Detroit to the hills of Appalachia to the quiet lanes of Newtown, know that they are cared for, and cherished, and always safe from harm. 

That is our generation's task - to make these words, these rights, these values - of Life, and Liberty, and the Pursuit of Happiness - real for every American.  Being true to our founding documents does not require us to agree on every contour of life; it does not mean we will all define liberty in exactly the same way, or follow the same precise path to happiness.  Progress does not compel us to settle centuries-long debates about the role of government for all time - but it does require us to act in our time. 

For now decisions are upon us, and we cannot afford delay.  We cannot mistake absolutism for principle, or substitute spectacle for politics, or treat name-calling as reasoned debate.  We must act, knowing that our work will be imperfect.  We must act, knowing that today's victories will be only partial, and that it will be up to those who stand here in four years, and forty years, and four hundred years hence to advance the timeless spirit once conferred to us in a spare Philadelphia hall.

My fellow Americans, the oath I have sworn before you today, like the one recited by others who serve in this Capitol, was an oath to God and country, not party or faction - and we must faithfully execute that pledge during the duration of our service.  But the words I spoke today are not so different from the oath that is taken each time a soldier signs up for duty, or an immigrant realizes her dream.  My oath is not so different from the pledge we all make to the flag that waves above and that fills our hearts with pride. 

They are the words of citizens, and they represent our greatest hope. 

You and I, as citizens, have the power to set this country's course. 

You and I, as citizens, have the obligation to shape the debates of our time - not only with the votes we cast, but with the voices we lift in defense of our most ancient values and enduring ideals. 

Let each of us now embrace, with solemn duty and awesome joy, what is our lasting birthright.  With common effort and common purpose, with passion and dedication, let us answer the call of history, and carry into an uncertain future that precious light of freedom. 

Thank you, God Bless you, and may He forever bless these United States of America.

Friday on "NBC Nightly News," Dr. Nancy Snyderman reported on an organization that's salvaging food left behind on fields and orchards, providing free produce to those who can't afford it. Click here to visit the Hidden Harvest website. 

As President Barack Obama is set to begin his second term next week, he finds himself with a job-approval rating above 50 percent and with majorities supporting his general direction on gun control and immigration, according to a new NBC News/Wall Street Journal poll.

But he also confronts an American public holding mixed attitudes about the next four years, concerns about the economy and a belief that tougher times lie ahead.

Click here for the full poll (.pdf)

It’s a stark reversal from four years ago, when Obama’s first inauguration – despite taking place in the midst of the Great Recession – contained high expectations and seemed more like a “coronation,” says Democratic pollster Peter D. Hart, who conducted the survey with Republican pollster Bill McInturff.

“If 2009 was all about hope, 2013 is about the ability to cope,” Hart adds of the public’s lower expectations about the economy and reducing partisanship in Washington.

General support for Obama’s gun, immigration agenda
In the poll, 52 percent of adults approve of the president’s overall job performance, which is down one point from last month. In addition, 49 percent approve of his handling of the economy, versus 48 percent who disapprove.

What’s more, the public appears to be receptive to the broad outlines of his top agenda items for a second team.

Mandel Ngan / AFP - Getty Images file

President Barack Obama speaks on proposals to reduce gun violence on Jan. 16, 2013 in the South Court Auditorium of the Eisenhower Executive Office Building, next to the White House in Washington.

Fifty-six percent believe that the laws covering the sale of firearms should be stricter, compared with a combined 42 percent who want them less strict or kept the same.

That’s the most support on this particular question since 2006, but it’s less than the 60 percent to 70 percent who supported stricter gun laws during the 1990s, including when Congress passed an assault-weapons ban in 1994.

Related: NRA more popular than entertainment industry, poll says

Also, for the first time in the poll, a majority of Americans -- 52 percent -- favor allowing illegal immigrants who hold jobs to apply for legal status in this country.

And in the latest fiscal fight in Washington, more respondents say they would blame congressional Republicans (45 percent) than Obama and congressional Democrats (33 percent) if the nation’s debt limit isn’t raised and the country is unable to meet its obligations.

As for views on Obama’s qualities as president, he gets the best marks for being easygoing and likeable (61 percent give him high marks here), having the ability to handle a crisis (55 percent), being compassionate (53 percent), being knowledgeable and experienced (53 percent) and being a good commander in chief (51 percent).

His lowest marks come on achieving his goals (44 percent give him high marks here), working effectively with Congress (29 percent) and changing business as usual in Washington (28 percent).

'A lack of buoyancy'
Yet looking ahead to Obama’s next four years in office, Americans have tempered their expectations.

The public is split how Obama will fare in a second term, with a majority of respondents -- 51 percent -- saying they’re either “optimistic” or “satisfied.”

By comparison, a combined 48 percent say they are “uncertain” or “pessimistic.”

Asked another way, 43 percent are optimistic about the next four years, while 35 percent are pessimistic; 22 percent have a mixed opinion.

In addition, more than seven in 10 are dissatisfied with the current state of the economy, and just more than a third are either “very” or “fairly” confident in Obama’s ability to promote a strong and growing economy.

And 60 percent believe the coming year will be a time to hold back and save because of harder times ahead, versus 34 percent who instead think it will be a time of economic expansion and opportunity.

“The poll reveals a lack of buoyancy in looking ahead,” Hart, the Democratic pollster, says.

Adds GOP pollster McInturff: “This feels like a long four years, and it feels like a long four years ahead.”

Public continues to sour on Congress, GOP
But if Americans have tempered the expectations for Obama’s second term, they have soured even more on Congress and the Republican Party.

Just 14 percent of adults approve of Congress’ job (which is near the all-time low in the poll), while 81 percent disapprove (which is close to its all-time high).

What’s more, 49 percent hold a negative view of the Republican Party – its highest negative rating in the survey since 2008. Only 26 percent have a positive view.

By comparison, the Democratic Party has a net positive rating, with 44 percent holding a favorable view of the party and 38 percent holding an unfavorable one.

And the conservative Tea Party movement – which took off in Obama’s first year as president – also finds its popularity at an all-time low in the poll, with 23 percent viewing it favorably and 47 percent unfavorably.

On Iraq and Afghanistan
Soon approaching the 10-year anniversary of the Iraq war, nearly six-in-10 say the war wasn't worth it, versus 35 percent who say it was.

Yet asked another way, 55 percent of respondents think the war was successful.

Meanwhile, a narrow majority of Americans – 51 percent – say the war in Afghanistan hasn’t been worth it, though 62 percent believe the war there has been successful

The NBC/WSJ poll was conducted Jan. 12-15 of 1,000 adults (including 300 cell phone-only respondents), and it has an overall margin of error of plus-minus 3.1 percentage points.

Mike Ehrmann / Getty Images

Manti Te'o warms up before Notre Dame's game against the Crimson Tide on Jan. 7.

College football star Manti Te'o says he was the victim of a cruel hoax, an elaborate scheme in which he fell for an imaginary girlfriend named Lennay Kekua and mourned her when she died of leukemia.

But he still has a lot of explaining to do.

The narrative crafted before and after the expose is full of conflicting information and holes bigger than those in Notre Dame's defensive line during its loss to Alabama.

If Te'o wants the public to believe that he was nothing more than a dupe, here are some of the questions and inconsistencies he'll need to clear up.

1. Notre Dame says that Te'o never met Kekua, that their relationship was strictly online and by phone. But the player's father gave the South Bend Tribune a detailed account of how the couple first met at a Stanford game in Palo Alto in 2009 and rendez-voused in Hawaii after becoming a couple in early 2012. And Te'o himself told ESPN that she was the "most beautiful girl I ever met."

2. Te'o called Kekua "the love of my life." His parents said they believed they would get married. Yet if Notre Dame's account is to be believed, they never met even once, or even Skyped. It beggars belief.

3. Before her leukemia "diagnosis," Kekua supposedly was nearly killed in a car accident. But published profiles of Te'o have conflicting dates -- late 2011, last January, or as recently as April. Why the discrepancies?

4. When did Kekua's fictitious death happen? Various interviews with Te'o have her succumbing to leukemia hours before his grandmother died on Sept. 12, soon after, or even days after. Assuming Te'o truly believed Kekua had passed away, wouldn't he remember the date? Or did all the reporters get the details wrong?

5. After he supposedly received the shock of his life -- a call from someone using Kekua's voice and phone number while he was at the ESPN Awards on Dec. 6 -- Teo stayed quiet for three weeks. It wasn't until Dec. 26 that he told Notre Dame officials, who then hired private investigators to look into it.

6. If Te'o was in on the deception, though, why wouldn't he just let Kekua rest in peace? Was he or someone else worried the hoax was about to come to light, prompting a fourth-quarter end-run to get ahead of the revelations?

7. Hours after Deadspin's bombshell report and Notre Dame's press conference, when it seemed that everyone could agree on one thing -- there is no Lennay Kekua -- an NFL player claimed to have actually seen her in the flesh. Arizona Cardinals fullback Regan Mauia said he met her in American Samoa in 2011, before she started romancing Te'o, and is "close" to her family.

8. Carrying out the hoax would have been a full-time job involving more than one person. Te'o claims he would spend all night on the phone with Kekua while she was in the hospital. There were purported communications from family members. Who would have had the time to orchestrate it? By the same token, how would Te'o have been able to create and maintain a social-media profile for Kekua on his own?

9. Where's the motive? A central figure in the hoax is reported to be musician Ronaiah Tuiasosopo. Deadspin reported that he had contact with the woman, a former high-school classmate, whose photos were used to create Kekua's profile -- even obtaining one of the pictures from her directly. But the site also describes Tuiasosopo as a friend of Te'o, raising the question of why he would humiliate his buddy.

Related:

The legend of Manti Te'o just got more complicated
From Milli Vanilli to Balloon Boy: The greatest hoaxes in American history

Reporter: Believing Manti Te'o makes a great deal of faith

Updated 2:56 p.m. -- President Barack Obama unveiled sweeping new policies Wednesday aimed at limiting gun violence, teeing up a political showdown that will pit the broad public popularity for many gun control measures against Congress’s tepid appetite for approving the most stringent restrictions on gun ownership.  

"While there is no law or set of laws that can prevent every senseless act of violence completely, no piece of legislation that will prevent every tragedy, every act of evil," Obama said at a mid-day announcement at the White House, "if there's even one thing we can do to reduce this violence, if there's even one life that can be saved, then we've got an obligation to try it."

Acknowledging the difficulty of the Congressional fight ahead, Obama appealed for public support, slamming - as he did in a press conference earlier this week - conservative commentators and the most vocal pro-gun activists for "ginning up" opposition to gun reforms for political reasons. 

"I will put everything I've got into this and so will Joe [Biden], but I tell you, the only way we can change is if the American people demand it," he said. 

Some of the main legislative proposals backed by Obama and Vice President Joe Biden are:

• requiring criminal background checks on all gun sales, including private sales    
• banning "military-style" assault weapons    
• limiting ammunition magazines to 10 rounds      
• strengthening penalties for gun trafficking 

"The most important changes we can make depend on Congressional action," Obama said. "They need to bring these proposals up for a vote and the American people need to make sure that they do."

Related Information: Gun Violence Fact Sheet | Gun Violence Executive Summary | Gun Violence Reduction Executive Actions 

The president also signed a series of 23 executive actions - free from a Congressional blockade -- intended to strengthen existing laws, augment mental health measures and promote federal research on gun crime through the Centers for Disease Control. 

The executive actions announced included stricter prosecution of would-be gun buyers who fail background checks as well as new requirements for federal law enforcement to trace guns recovered in criminal investigations. 
 

The president's recommendations also direct administration officials to "clarify that the Affordable Care Act does not prohibit doctors asking their patients about guns in their homes" and to "release a letter to health care providers clarifying that no federal law prohibits them from reporting threats of violence to law enforcement authorities." 

Obama and Biden were joined at the White House event by families of the Newtown school shooting victims as well as by four children who wrote the president after the tragedy that left 20 young students dead. 

"This is our first task as a society: keeping our children safe," Obama said at the beginning of his remarks. "This is how we will be judged, and their voices should compel us to change."

Biden, who led the presidential task-force on gun safety in the wake of the Newtown shootings, praised the activists who met with his staff over the last week to help build the list of recommendations. 

"The world has changed and it's demanding action," Biden said. 

While some of Obama's long-expected proposals - like universal background checks - garner overwhelming public support, the outlawing of certain types of weapons may be less of a slam dunk for lawmakers eager to appease constituents. 

A recent poll from the Pew Research Center showed that a majority of Americans -- 55 percent -- back a ban on "assault-style weapons," with 40 percent saying they don't approve of a ban. But a partisan breakdown shows that only about four in ten Republicans support such restrictions, compared to a broad majority of Democrats. 

Democrats in Congress have already voiced doubts about the feasibility of the president's most ambitious proposals. 

"We're not going to get an outright ban" on assault weapons, Democrat Rep. Carolyn McCarthy of New York bluntly said yesterday.

 "[Senate Majority Leader] Reid has said he doesn't know whether he has the votes (for an assault weapons ban)," she added. "There's heavy lifting, so are we going to waste time on heavy lifting? Or are we going to try to work on doing something that could actually get passed?"

Related: Obama's gun plans spark little enthusiasm with key lawmakers

Supporters are more optimistic about background checks and magazine restrictions. 

Senate Judiciary Committee Chairman Patrick Leahy announced Wednesday that his panel will hold its first hearing on issues relating to gun violence on Jan. 30.

In his remarks Wednesday, Obama anticipated opponents' reactions to his proposals. 

"This will be difficult," he said. "There will be pundits and politicians and special interest lobbyists publicly warning of a tyrannical all-out assault on liberty. Not because that's true, but because they want to gin up fear or higher ratings or revenue for themselves, and behind the scenes they will do everything they can to block any commonsense reform and make sure nothing changes whatsoever."

The National Rifle Association, the country's most powerful gun lobby, released a statement Wednesday afternoon in response to the president's remarks.

"We look forward to working with Congress on a bi-partisan basis to find real solutions to protecting America's most valuable asset - our children. Attacking firearms and ignoring children is not a solution to the crisis we face as a nation," the NRA wrote. "Only honest, law-abiding gun owners will be affected and our children will remain vulnerable to the inevitability of more tragedy."

That statement was relatively muted in comparison to the group's controversial ad released Tuesday night, which criticized Obama's dismissal of the gun lobby's proposal to increase armed security in schools. 

"Are the president's kids more important than yours?" a narrator asks in the short ad. "Then why is he skeptical about putting armed security in our schools when his kids are protected by armed guards at their schools? Mr. Obama demands the wealthy pay their fair share of taxes, but he's just another elitist hypocrite when it comes to a fair share of security."

Related: White House calls NRA 'repugnant,' 'cowardly' for invoking president's children in ad

The ad prompted outcry from observers who said the First Family should be off limits for such advertisements, while NRA backers say their focus is on school safety rather than on the president's daughters themselves. 

"Whoever thinks the ad is about President Obama's daughters are missing the point completely or they're trying to change the subject," said spokesman Andrew Arulanandam. "This ad is about keeping our children safe. And the president said he was skeptical about the NRA proposal to put policemen in all schools in this country. Yet he and his family are beneficiaries of multiple law enforcement officers surrounding them 24 hours a day." 

White House spokesman Jay Carney shot back that the ad is "cowardly." 

"Most Americans agree that a president's children should not be used as pawns in a political fight," he said. "But to go so far as to make the safety of the President's children the subject of an attack ad  is repugnant and cowardly."

NBC's Mark Murray, Frank Thorp, Ali Weinberg and Kelly O'Donnell contributed to this report.