nbc news chief science correspondent robert bazell has our report. >> who's a smart guy? >> me. >> yes, you are. >> it's one more piece in the gigantic puzzle called autism. scientists have found that women who were obese are 1.6 times as likely to have a baby with autism or some other developmental disorder and twice as likely if they have diabetes. but they emphasis the study of the mothers of about 1,000 kids is an observation, not scientific proof of cause and effect. >> if you are planning a pregnancy, you may think about losing weight and getting your exercise routine in order, and making sure you are controlling your blood sugar. >> everything is going good? >> dr. anna sanchez in st. joseph hospital in orange county, california, has been working for years to get pregnant women to keep their weight under control. >> perfect. >> because overweight moms can have kids with many health problems. she says the latest results only add to the urgency. >> if people are overweight when they start the pregnancy, they should gain less than the recommended weight gain. >> that'

here is nbc's chief science correspondent, robert bazell. >> it's a nightly struggle waged by tens of millions of american workers. beating the clock and somehow getting enough sleep. but many of us are losing. and today, the government put a number on it. >> unfortunately, what we found is that about a third of working adults get only six or fewer hours every day of sleep. >> those most sleep deprived are those on the night shift. among health care workers, just over half said they don't sleep enough. for those in the transportation and delivery business, it was 70%. many studies have shown a lack of sleep increases the risk for all sorts of health problems including heart disease, obesity and diabetes, and it is responsible for 20% of car crashes. the cdc says people who work nights should adopt a regular sleep routine. on the night shift at brigham young women's hospital in boston, some people like nurse steven mcgovern say they actually do better working nights. >> even when i was younger, i was a night person. i would have trouble sleeping at night, i was up all night. >> but mos

our report tonight from our chief science correspondent robert bazell. >> reporter: the cow was found at a recycling plant for dead livestock in hanford, california. u.s. officials insists it presents no threat to human health. >> this particular animal did not enter the food supply at any time. so there is no concern about that. >> reporter: bse, commonly called mad cow disease, is a fatal disintegration of the brain and nervous system. it first gained public attention in britain in the 1980s and '90s where more than a million cattle were affected, and where more than 4.4 million cattle were with slaughtered to control the outbreak. the disease is usually transmitted by a rare infectious agent called a prion. though cases can appear spontaneously. usually the disease is acquired by eating the tissue of an infected animal. animals had been a common source of food for cows in britain. in britain, 175 people including jonathan sims got a human form of the disease by eating meat from the infected animals. health officials say milk does not transmit the disease, so the infected dairy cow

robert bazell, nbc news, oakland. >> nice story to end on for a wednesday night.hank you for being here with us. i'm brian williams, and the evening is not over. we hope to see you right back here tonight for "rock center" at 9:00, 8:00 central, and of course, tomorrow evening back here for "nightly news." good night. >>> and good evening, everyone. i'm jessica aguirre. >> and i'm raj mathai. the rain has arrived. the bay area getting wet as we speak. two systems rolling into town for this midweek storm. let's bring in our chief meteorologist jeff ranieri who is tracking the timing of this rain from our nbc bay area weather center. >> doppler radar shows us picking up our first rain drops while this is not a strong storm it's a may skror departure from what we had this weekend where temperatures were record setting in the 80s and the 90s as we zoom in what you'll find is some of this activity in south san jose near downtown, also near cambria park.

robert bazell, nbc news, new york. >>> when we come back, a baby boom on the west coast, in one placen particular, and a pretty good idea why it's happening. when i take a picture of this check, it goes straight to the bank. oh. oh look the lion is out! no mommy no! don't worry honey, it only works on checks. deposit checks from your smartphone with chase quickdeposit. just snap a picture, hit send and done. take a step forward and chase what matters. >>> there are still a couple of things you can't say these days, or if you choose to, be ready. if you're the manager of the miami marlins and your stadium is located in the little havana neighborhood, you can't stick up for fidel castro. you can't say as, the marlins manager, ozzie guillen did, that you love and respect fidel castro. the marlins have suspended him for five games. he apologized at a news conference today, speaking mostly in spanish, and said he was "very guilty, very sad and very embarrassed." >>> the second of three winning tickets in that giant $656 million mega millions lottery has been claimed in maryland. like the w

nbc's chief science correspondent robert bazell explains. >> reporter: just when most americans are getting their normal sleep, 21 million others are working nights. >> i average maybe four hours a day and even on my nights off i average maybe 3 1/2, 4 hours of sleep. so i'm always tired. >> reporter: as she works at the women's hospital in boston, where new research provides further evidence how harmful shift work can be. scientists put 21 healthy volunteers in the sleep lab for three weeks. by changing lights irregularly and taking away clocks and other clues about time, they altered the subjects' normal body clocks. within just a few days when the volunteers ate, their bodies responded differently to the food with dangerous effects. >> glucose levels went higher and stayed that way for several hours. this was because of decreased insulin release from the pancreas. together these reflect an increased risk of diabetes. >> reporter: several studies have shown shift workers are at higher risk for type 2 diabetes, heart disease and other problems. this study is one of the first to show exactl

robert bazell, nbc news, oakland. >> nice story to end on for a wednesday night.for being here with us. i'm brian williams, and the evening is not over. we hope to see you right back here tonight for "rock center" at 9:00, 8:00 strl, and of course, tomorrow evening back here for "nightly news." good night.

we get the story from robert bazell. >> 21 million people are working nights when others are gettingp. >> i average maybe four hours a day. and even on my nights off i average 3 1/2, 4 hours of sleep. i'm always tired. >> reporter: she works at a research hospital in boston where there's new evidence about how harmful shift work can be. scientists put 21 volunteers in the sleep lab for three weeks. by talking away clues about time, they altered the normal body clocks. within just a if uh days when the volunteers ate, their bodies respond eed differently to food. >> glucose levels stayed higher for hours because of increased insulin release in the pancreas. >> reporter: several studies have sthoun that shift workers are at risk for diabetes, heart disease and other problems, but this study is one of the first to show exactly how the body is harmed. the diabetes risk was so great that three of the healthy people in the studies became prediabetes during the experiment. three weeks after the shift in wake cycle they returned to normal. for paula and her co-workers, they know how difficul

robert bazell, nbc news, new york. >>> when we come back, a baby boom on the west coast, in one placen particular, and a pretty good idea why it's happening. you wouldn't want your doctor doing your job. so why are you doing his? only your doctor can determine if your persistent heartburn is actually something more serious... like acid reflux disease. over time, stomach acid can damage the lining of your esophagus. for many, prescription nexium not only provides 24-hour heartburn relief, but can also help heal acid related erosions in the lining of your esophagus. talk to your doctor about the risk for osteoporosis-related bone fractures and low magnesium levels with long-term use of nexium. possible side effects include headache, diarrhea and abdominal pain. other serious stomach conditions may still exist. let your doctor do his job, and you do yours. ask if nexium is right for you. if you can't afford your medication, astrazeneca may be able to help. is the pain reliever orthopedic doctors recommend most for arthritis pain, think again. and take aleve. it's the one doctors recommen

robert bazell, nbc news, bethesda. >> may of 1990, that report.9, seven members of the same protest group had chained themselves to the balcony at the new york stock exchange and infurled a banner that said sell welcome. they made azt, only aids drug, technically at a cost of $10,000 a year in 1989 llars. new york stock exchange had trading stopped. the group that did all of this was act up, the aids coalition to release power. it was founded 25 years ago this week. by playwright larry kramer. the medical journals were writing about something that would later be called aids, killing people in every-increasing numbers as early as 1981, by the time 1987, when act up was thousands, 37,000 had been diagnosed and 20,000 americans had died, and the president of the united states, ronald reagan, had never said the word aids in public. 20,000 dead americans, all in his time in office, before he ever said a word about it. this week to mark the 25th anniversary of the founding of act up, one of the most effective activist groups in american history, long-ti

robert bazell, nbc news, bethesda. >> that was in may of 1990, that report. in the fall of 1989, seven members of the same protest group had chained themselves to the balcony at the new york stock exchange and the opening bell and unfurled a banner that said sell welcome. welcome was the company that made azt, the only real aids drug available at that time. available, technically, at a cost of $10,000 a year in 1989 dollars. the new york stock exchange had trade halted that day for the first time, that was not due to wartime. the company dropped the price of azt soon after the demonstration. the group that did all of this was act up, and it was founded 25 years ago this week. in a speech my playright larry kramer. the medical journals were writing about something that would later be called aids, killing people in every-increasing numbers as early as 1981, by the time 1987, when act up was founded, 37,000 had been diagnosed and 20,000 americans had died. and the president of the united states ronald reagan had never said the word aids in public. 20,000 dead am

nbc news chief science reporter robert bazell will have more on the effect of mad cow disease at 5:30 on nightly news. >>> place of a hostage helped end a standoff with a would-be bank robber today. the harrowing ordeal at the as well as fargo in downtown hayward. a man walk with a note and demanded money and told every ton drop to the ground, saying he was going to blow things up. police say the still unidentified suspect held the knife to the threat of a pregnant woman. after she told him she was pregnant and after further pleas from the crisis negotiator, the bank robber let the woman go and was taken into custody himself with not one person in the bank physically hurt. >>> hundreds of protesters marched down to wells fargo headquarters where a shareholder meeting was underway. 24 people were arrested for had trespassing, including the 14 who had to be escorted out of the meeting. many hold certificates to prove they own shares or were there serving as proxies for other shareholders. despite waiting for hours, many were not allowed inside to speak directly to bank execs. >> wells f

so far it's one cow. >> robert bazell, thank you.you on our other sister networks all day long. still to come this morning apple, the fed earnings and much more. jeremy siegel gives us his outlook. and mohamed el-erian with his latest market predictions. "squawk" will be right back. duff & phelps finds the sweet spot and investment banking services. that powers sound decisions.fy aye, or...a mornin' of tiny voices crying out, "feed us -- we've awakened from our long winter's nap and we're peckish to the point of starvin'"!! i don't understand... your grass, man! it's a living, breathing thing. it's hungry, and you've got to feed it with scotts turf builder. that a boy, mikey! two feedings now...in the springtime strengthens and helps protect your lawn from future problems. [ scott ] get scotts turf builder lawn food. it's guaranteed. feed your lawn. feed it! it's guaranteed. between listening to the numbers... ...and listening to your instinct. duff & phelps finds the sweet spot that powers sound decisions. duff & phelps financial ad

robert bazell is nbc's chief science correspondent. bob, good to see you. good morning. >> good morning, matt. although this is the fourth confirmed case in the united states since 2003, and officials are still investigating how a dairy cow contracted the disease. the government is stressing there is no threat to human health. the dairy cow had been picked up by this facility near fresno, california, that takes dead live stock. the facility sent a sample to be tested at the lab at the university of california davis where it turned out positive. there was never an intention to send the cow to a slaughterhouse and officials say that is you're. >> the animal did not enter the food supply at all. >> reporter: bsc, commonly called mad cow disease is a fatal disintegration of the brain and nervous system. it first gained public attention in britain in the 1980s and '90s where more than 180,000 cattle were infected and more than 4.4 million were slaughtered to control the outbreak. the disease is usually transmitted by a rare infectious agent called a prion, thoug