Scientists: Hazardous asteroids may be more numerous
New analysis of Chelyabinsk event in Russia says asteroid hit with energy of 30-plus Hiroshima atom bombs.
Medicare chief testifies about HealthCare.gov’s problems
Site will be working smoothly for most consumers by the end of the month, Marilyn Tavenner told the Senate.
Scientists say Earth-size, temperate planets common
The Milky Way galaxy alone could have about 25 billion rocky worlds in “habitable zones” of stars.
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Johnson & Johnson to pay $2.2B in fraud case
![Johnson & Johnson to pay $2.2B in fraud case](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/11/04/Health-Environment-Science/Images/Johnson__Johnson_Risperdal-0eb17-1607.jpg)
Company agrees to pay $2.2 billion to resolve probe into its marketing of Risperdal, other prescription drugs.
A mouse that took on a scorpion
![A mouse that took on a scorpion](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/11/04/Web-Resampled/2013-11-04/Rowe71383253281-kHh--90x60@wp.com.jpg)
The tiny southern grasshopper mouse can attack scorpions without feeling pain from its stinging tail.
Does your dog wag his tail to the left or right? It matters.
![Does your dog wag his tail to the left or right? It matters.](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/11/03/Production/Health/Images/bigstock-Beagle-Dogs-8023113.jpg)
To study reactions to other dogs’ waggings, researchers monitored the heart rate of 43 dogs.
10 ways to prevent allergic reactions
![10 ways to prevent allergic reactions](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/11/03/Production/Health/Images/bigstock-Pillow-3852013.jpg)
There is a lot of conventional wisdom about allergies — and how to handle them — and not all of it is right.
Pulmonary arterial hypertension can be fatal if untreated
![Pulmonary arterial hypertension can be fatal if untreated](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/11/04/Web-Resampled/2013-11-04/Student_Athlete_Heart_Screening-01046-kT--90x60@wp.com.jpg)
Shortness of breath and undue fatigue are symptoms that require persistent medical investigation.
In the ‘gray zone’: A newborn baby and a doctor’s dilemma
![In the ‘gray zone’: A newborn baby and a doctor’s dilemma](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/07/19/Production/Health/Images/newborniStock.jpg)
A neonatologist must decide whether to revive a premature baby on the borderline of viability.
Female success may be bad for the male ego
![Female success may be bad for the male ego](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/10/28/Health-Environment-Science/Images/Old_World_The_Silent_Years-05ca1-1533.jpg)
A study says a woman’s success made her male partner feel worse about himself than her failure did.
Soccer star tending to a new goal
![Soccer star tending to a new goal](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/11/01/Health-Environment-Science/Images/CROPBrianas7Portrait.jpg)
World Cup champion Briana Scurry fights back from the concussion that ended her career, clouded her life.
Multimedia
Small worlds revealed
The winners of the 2013 Nikon Small World competition for microscope photography.
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Mediterranean diet may be tied to better health in later life
![Fillet of salmon with asparagus](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/11/03/Production/Health/Images/iStock_000017176125Medium.jpg)
Study finds eating less meat and more fish, nuts, fruit and vegetables may make for a healthier old age.
A patient in a vegetative state shows awareness and focus
![WASHINGTON, DC. MAY 21, 2013: A brain scan is used in a demonstration with 3D Haptic Touch which can be applied to medical and robotics, at Microsoft TechFair in Washington, DC on May 21, 2013. ( Photo by Jeffrey MacMillan )](https://webarchive.library.unt.edu/web/20131106190512im_/http://www.washingtonpost.com/rw/sites/twpweb/img/blogs/spacer.gif)
New study raises possibility of using devices someday to allow such people to communicate.
Filth taints 12 percent of imported food spices, FDA reports
![A batch of coarsely ground red peppers is pictured near Batya, 140km south of Budapest September 21, 2013. Many are hoping to put Hungary's once booming paprika business, a powdered spice that has long been a staple in Hungarian cooking, back on the map after decades of neglect and despite fierce competition from countries including Brazil, Serbia and China. Picture taken September 21, 2013. To match story FOOD-HUNGARY/PAPRIKA REUTERS/Laszlo Balogh (HUNGARY - Tags: AGRICULTURE BUSINESS FOOD)](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/10/07/Travel/Images/2013-09-26T191737Z_01_BAL13_RTRIDSP_3_FOOD-HUNGARY-PAPRIKA.jpg)
Mexico had the highest percentage of exports of contaminated spices, followed by India.
Mathematical ability seems to be evident even in infancy
![SciScan1105](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/11/03/Production/Health/Images/bigstock-Math-Class-42984103.jpg)
Also, a new book relies on common experiences to explain scientific principles.
Another reason why men don’t do yoga
![BETHESDA, MD - OCTOBER: 10 Yoga instructor Adrian Hummell teaches Bikram Yoga classes in Bethesda, Maryland. He is photographed on October 10, 2013. (Photo by Marvin Joseph/The Washington Post)](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/11/04/Web-Resampled/2013-11-04/HEmanyoga03B1381462512-k9kG--90x60@wp.com.jpg)
The problem is a lack of classes specifically for aging men, who are less limber, one reader says.
Kaiser Health News
AnyBODY
Why I’m waiting to buy insurance on the health exchanges
![FILE - In this Oct. 28, 2013, file screenshot, the U.S. Department of Health and Human Services' main landing web page for HealthCare.gov. Members of Congress are governing themselves under President Barack Obama’s signature law, which means they have great leeway in how to apply it to their own staffs. For lawmakers, it is about a section of the law that may _ or may not _ require them to toss some staffers off of their federal health insurance and into the Affordable Care Act’s exchanges. (AP Photo/U.S. Department of Health and Human Services, File)](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/11/02/Production/WashingtonPost/Images/Congress_Health_Care_Confusion-0174f.jpg)
It’s not (just) the Web site problems. It’s the price.
Why is it still so hard to diagnose ADHD?
![Students arrive for class at Mahnomen Elementary School in Mahnomen, Minnesota September 26, 2013. The U.S. government may have headed off some of the most dire predictions about the 'sequester,' but over seven months, the across-the-board spending cut has thrown sand into the gears of the economic recovery. Mahnomen school district, which serves the White Earth Indian reservation in Minnesota, lost 3 percent of its funding due to the sequester. The district didn't replace a teacher who retired and has scaled back on homework tutoring and an alternative-school program for teenage mothers. Another year of cuts could force the school to lay off teachers and scale back bus service, superintendent Jeff Bisek says. To match Insight USA-BUDGET/SEQUESTER Picture taken September 26, 2013. REUTERS/Dan Koeck (UNITED STATES - Tags: EDUCATION POLITICS BUSINESS)](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/10/25/Education/Images/2013-09-28T110648Z_01_DKK103_RTRIDSP_3_USA-BUDGET-SEQUESTER.jpg)
School personnel play a big role in diagnosing the disorder, but they may not be best equipped for the job.
Can physical activity help kids do better in school?
![First Lady Michelle Obama jogs with children at a back-to-school event at Orr Elementary School in the District last month.](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/10/17/Health-Environment-Science/Images/RTX13A1I1382041861.jpg)
Yes, studies say, they will test better. But whether being active helps them learn better is still unresolved.
How & Why/EcoLOGIC
The genetic mutants that led to a Nobel
![epa03900401 Handout image released 07 October 2013 by the University of California, Berkeley of professor Randy W. Schekman who shares the 2013 Nobel Prize in Physiology or Medicine with James E. Rothman and Thomas C. Sudhof for 'for their discoveries of machinery regulating vesicle traffic, a major transport system in our cells.' EPA/UC BERKELEY / HANDOUT EDITORIAL USE ONLY, NO SALES](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/10/07/Production/WashingtonPost/Images/03900401.jpg)
How Randy Schekman transformed a simple idea into the basis for a hepatitis vaccine.
N.Y. chefs test whether chickens’ diet affects their taste
![HEHow1001](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/09/26/Production/Health/Images/iStock_000013816664Medium.jpg)
Experts say it may be easier to manipulate the flavor of eggs rather than that of flesh.
How bad for the Earth are gas-powered leaf blowers?
![FILE- In this Sept. 12, 2012, file photo, a red leaf hangs from a tree in Greensboro, Vt. Vermont officials are rushing to the defense of one of the state’s most cherished icons, fall foliage, after an Arizona magazine claimed the fall colors in the Grand Canyon state are better than the Green Mountains after they have turned red, gold and orange. The cover of the October edition of the magazine Arizona Highways shows a picturesque scene of a bucolic waterfall surrounded by golden foliage while carrying the headline “Autumn in Arizona & Why it’s better than it is in Vermont. (AP Photo/Toby Talbot, File)](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/09/16/Health-Environment-Science/Images/Foliage_Fight-01f85.jpg)
Pretty bad. But don’t get all high and mighty about your rake. Your lawn mower isn’t innocent, either.
Medical Mysteries
Emergency surgery followed many missed chances to diagnose illness
![HSCover0813](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/08/12/Health-Environment-Science/Images/WP_MedMystAug_Fin08HiRes.jpg)
Until he nearly died, the reason for Kevin Songer’s weak muscles went undetected for more than 50 years.
Joint replacement had gone well, but patient’s shoulder still hurt
![Original artwork by Owen Freeman. All rights reserved.](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/07/22/Web-Resampled/2013-07-22/WP_MedMystJul_Fin07HiRes-kPLB--90x60@wp.com.jpg)
Woman endured years of surgery and pain before the mystery of her ailment was solved.
Health, Science & Environment Videos
![Kliff Notes: Will Obamacare cancel my plan? Kliff Notes: Will Obamacare cancel my plan?](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_296w/2010-2019/WashingtonPost/2013/11/04/InPlay/Images/IP_KLIFF-CANCELLATIONS_110413-a.jpg)
Kliff Notes: Will Obamacare cancel my plan?
Wonkblog's Sarah Kliff explains why a lot of people's health insurance policies might get cancelled.![Kliff Notes: HealthCare.gov's 3 problems Kliff Notes: HealthCare.gov's 3 problems](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/10/25/InPlay/Images/IP_KLIFF-PROBLEMSa_102513_60_x_90.jpg)
Kliff Notes: HealthCare.gov's 3 problems
Wonkblog's Sarah Kliff walks through the three main problems bogging down the Affordable Care Act's online marketplace.![Kliff Notes: Obama's healthcare speech Kliff Notes: Obama's healthcare speech](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/10/22/InPlay/Images/22obama_60_x_90.jpg)
Kliff Notes: Obama's healthcare speech
Wonkblog's Sarah Kliff shares her "Kliff Notes" for President Obama's remarks defending his signature healthcare law.![Obamacare Q&A: Are all marketplaces created equal? Obamacare Q&A: Are all marketplaces created equal?](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/10/09/InPlay/Images/IP_KLIFF-QA-STATES_100913_60_x_90.jpg)
Obamacare Q&A: Are all marketplaces created equal?
Wonkblog's Sarah Kliff explains why the Affordable Care Act's health insurance marketplaces are different from state to state.![Obamacare Q&A: Who doesn't have to enroll? Obamacare Q&A: Who doesn't have to enroll?](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/10/04/InPlay/Images/IP_KLIFF-QA-EXEMPTIONS-e_100413_60_x_90.jpg)
Obamacare Q&A: Who doesn't have to enroll?
Wonkblog's Sarah Kliff explains the exceptions to the Affordable Care Act's individual mandate.![Obamacare Q&A: What if I already have insurance? Obamacare Q&A: What if I already have insurance?](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/10/03/InPlay/Images/IP_KLIFF-QA-COMPANY-b_100313_60_x_90.jpeg)
Obamacare Q&A: What if I already have insurance?
Wonkblog's Sarah Kliff explains how insured people can use the Affordable Care Act's health insurance marketplaces.![Obamacare Q&A: Can anyone deny me coverage? Obamacare Q&A: Can anyone deny me coverage?](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/10/01/InPlay/Images/IP_KLIFF-QA-CONDITIONS-B_100113_60_x_90.jpg)
Obamacare Q&A: Can anyone deny me coverage?
Wonkblog's Sarah Kliff explains what changes for people with pre-existing conditions under the Affordable Care Act.![Obamacare Q&A: Will I go to jail? Obamacare Q&A: Will I go to jail?](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/09/30/InPlay/Images/IP_KLIFF-QA-TAX-e_093013_60_x_90.jpg)
Obamacare Q&A: Will I go to jail?
Wonkblog's Sarah Kliff explains what happens if you don't buy health insurance under the Affordable Care Act.![Obamacare explained, in 2 minutes Obamacare explained, in 2 minutes](https://webarchive.library.unt.edu/web/20131106190512im_/http://img.washingtonpost.com/rf/image_90x60/2010-2019/WashingtonPost/2013/09/26/InPlay/Images/IP_OBAMACARE-EXPLAINED2_092613_60_x_90.jpg)
Obamacare explained, in 2 minutes
Wonkblog's Sarah Kliff breaks down the policy you need to understand about the Affordable Care Act, from politics to premiums.The Post Most: NationMost-viewed stories, videos and galleries int he past two hours