Chrome: If you're like me, you probably open a handful of tabs every day that you never even get around to actually looking at. TabZolo helps you prevent tab overload by keeping your browsing focused to only one tab at a time.
TabZolo brings you back to a bygone, tabless browsing era, but sometimes that's exactly what you need to stay focused. When you enable the extension, every tab except the one currently selected will disappear, and it will even prevent you from opening any new ones. When you need to use tabs again, just disable the extension, and all of the tabs that it previously closed will reappear right where you left them. It's a simple concept, but if you tend to bury yourself in a pile of webpages throughout the day, forcing yourself to only use one at a time can be a big help.
WASHINGTON (Reuters) - Housing starts and permits for future home construction unexpectedly fell in June, but the decline in activity was likely to be short-lived against the backdrop of bullish sentiment among home builders.
The Commerce Department said on Wednesday housing starts dropped 9.9 percent to a seasonally adjusted annual rate of 836,000 units. That was the lowest level since August last year.
Economists, who had expected groundbreaking to rise to a 959,000-unit rate, shrugged off the decline and said wet weather in many parts of the country had dampened activity. They noted that much of the drop was in the volatile multifamily segment.
"It looks like it's weather-related," said Sam Bullard, a senior economist at Wells Fargo Securities in Charlotte, North Carolina. "On the surface it doesn't look good, but we are confident that starts activity is still going to climb higher in the months to come."
Permits to build homes fell 7.5 percent last month to a 911,000-unit pace. Economist had expected permits to rise to a 1-million unit pace.
Though it was the second straight month of declines in permits, they remained ahead of starts. Economists said this, together with upbeat homebuilder confidence, suggested groundbreaking activity will bounce back in July and through the remainder of this year.
Sentiment among single-family home builders hit a 7-1/2 year high in July, a report showed on Monday, amid optimism over current and future home sales.
MORTGAGE RATES STILL LOW
There was little to suggest that a recent spike in mortgage rates was restraining home building activity, economists said, pointing to the improving builder confidence.
"New home supply and housing completions remain low, home prices are rising and, despite the recent rise, mortgage rates remain low," said John Ryding, chief economist at RDQ Economics in New York. "To us, this all points to housing activity adding to growth in the second half of the year."
Housing's recovery is being aided by still-low mortgage rates engineered by the Federal Reserve's accommodative monetary policy and steady employment gains.
Mortgage rates increased in recent weeks after the Fed expressed its desire to start cutting back on its bond purchases later this year. The monthly $85 billion in bond purchases have been holding down interest rates.
Fed Chairman Ben Bernanke said on Wednesday the central bank still expected to start scaling back its massive asset purchase program later this year, but left open the option of changing that plan in either direction if the economic outlook shifted.
The U.S. stock market rose as Bernanke's comments led markets to believe the central bank's plans to pull its monetary stimulus were not set in stone. The U.S. dollar gained ground while Treasury securities prices slipped.
Bernanke offered an upbeat assessment of the housing market's prospects.
"Housing activity and prices seem likely to continue to recover, notwithstanding the recent increases in mortgage rates, but it will be important to monitor developments in this sector carefully," Bernanke told lawmakers.
Last month, groundbreaking for single-family homes, the largest segment of the market, slipped 0.8 percent to its lowest level since last November 2012. Starts for multi-family homes declined 26.2 percent to a 245,000-unit rate.
Starts were down in all four regions in June, with big declines in the Northeast, South and the Midwest.
Weak groundbreaking suggested a smaller boost to both second and third quarter gross domestic product from residential construction. Second-quarter GDP estimates are ranging between 0.5 percent and 1 percent.
The economy grew at a 1.8 percent annual pace in the first three months of the year.
Permits for multi-family homes fell 21.4 percent last month. But permits for single-family homes rose 0.6 percent to a their highest since May 2008.
(Reporting by Lucia Mutikani; Editing by Andrea Ricci and Chizu Nomiyama)
I've read TFA, and thanks for adding some clarity, but I still have to wonder when they'll sequence the DNA.
Apparently you neither read the TFA nor the reply to your original false assertion that they didn't sequence the DNA.
Nor does your claim "if it's just an already known species then it's just contamination" make any sense.
I was on a remote island recently. I picked up an odd feather on the beach. I brought it back home and used it to identify the bird it came from. It was a known species.
There is absolutely no basis in that observation to support the claim that my backpack had somehow become contaminated by feathers from that species, and DNA is no different from feathers in this regard, when subject to ordinary standards of careful handling for such samples, which were obviously applied in this case (that is: the people doing the research are not and should not be presumed to be complete idiots.)
So you're completely wrong about all that, but have a nice day anyway!
Britain's bats could face difficulties this summer following two cold springs in a row, a charity suggests.
Latest figures from the National Bat Monitoring Programme revealed that fewer of the flying mammals were counted in 2012 than the previous year.
The Bat Conservation Trust is concerned that this year's "unseasonable start" could mean that bats struggle to bounce back.
However it suggested it is too early to tell if bats are on a downwards trend.
During the summer bat activity reaches its peak. But this year the animals are faced with the challenges of a delayed breeding season and a lack of winged insects on which they feed, according to the Bat Conservation Trust.
"After two years of long, wet winters and a particularly late and cold start to summer this year, the outlook isn't too promising for our bats," said Dr Kate Barlow, head of monitoring at the charity.
The latest report from the National Bat Monitoring Programme revealed the level of bat activity recorded in 2012. Common pipistrelle; soprano pipistrelle; noctule and serotine bat species were all lower in number than in 2011, and "roost counts" were down compared with the year before for six of the species.
Bat Conservation Trust's Philip Briggs explained breeding in bats appeared to be reduced or delayed last year, probably due to the cold spring and exceptionally wet summer.
"Female bats often skip a year with breeding, or would certainly delay breeding... This can mean that if a baby's born quite late in the summer, they've got less time to feed up and get to full size and strength before they go into hibernation, which could impact on their overwinter survival."
Mr Briggs speculated that this year, the bats' breeding season could again have been delayed due to the cold spring but added:
"I suppose if we continue with the current good weather this could help improve breeding success and survival throughout the summer, but we'll just have to see how things go."
Seventeen species of bats breed in the UK, including the rare Bechstein's bat, the distinctive-looking brown long-eared bat and the Daubenton's bat, also known as the "water bat" because it snatches insects from water surfaces.
Over the past 15 years, the National Bat Monitoring Programme has shown that the population trends for all of the surveyed bat species are increasing or stable.
However, Dr Barlow commented: "All our bats produce only one baby a year... so a few years of bad weather could have dramatic impact on numbers of bats if they are unable to find enough food to allow them to breed successfully."
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A major security flaw may be placing any Android smartphone bought over the last four years at risk for takeover by hackers, according to a security firm.
Continue reading
Bluebox Security, a San Francisco-based cybersecurity startup, says that nearly 900 million devices that run the Android operating system could be targeted. A hacker could then go as far as to take over the entire phone remotely or steal data from the device.
In a blog posted to the company's website, Bluebox CTO Jeff Forristal called the risk to both individual Android users and the platform itself "great."
"A malicious app can access individual data, or gain entry into an enterprise," Forristal wrote.
Forristal says that if a hacker is able to gain access to your phone, they have the ability to read emails, text messages and take any account information or passwords stored there. If the phone is fully taken over, that person would also be able to make phone calls, send text messages or even record calls.
Natasha Lomas of TechCrunch points out that the flaw has not been widely exploited and that Google, which produces and maintains Android, is likely working on a fix.
Google also says that they've modified the way developers can submit applications to the Google Play store to increase security.
A July 2 report from the International Data Council, which tracks smartphone sales and usage worldwide, indicated that 93 percent of all smartphone shipments over the first quarter of 2013 ran Android.
52 percent of all American smartphone users own a phone that runs Android, while 41.9 percent own an Apple iPhone.
The balancing act of producing more food sustainablyPublic release date: 4-Jul-2013 [ | E-mail | Share ]
Contact: University of Oxford Press Office press.office@admin.ox.ac.uk University of Oxford
A policy known as sustainable intensification could help meet the challenges of increasing demands for food from a growing global population, argues a team of scientists in an article in the journal Science.
The goal of sustainable intensification is to increase food production from existing farmland says the article in the journal's Policy Forum by lead authors Dr Tara Garnett and Professor Charles Godfray from the University of Oxford. They say this would minimise the pressure on the environment in a world in which land, water, and energy are in short supply, highlighting that the environment is often overexploited and used unsustainably.
The authors, university researchers and policy-makers from NGOs and the UN, outline a new, more sophisticated account of how 'sustainable intensification' should work. They recognise that this policy has attracted criticism in some quarters as being either too narrowly focused on food production or as representing a contradiction in terms.
The article stresses that while farmers in many regions of the world need to produce more food, it is equally urgent that policy makers act on diets, waste and how the food system is governed. The authors emphasise that there is a need to produce more food on existing rather than new farmland because converting uncultivated land would lead to major emissions of greenhouse gases and cause significant losses of biodiversity.
Sustainable intensification is the only policy on the table that could create a sustainable way of producing enough food globally, argues the paper; but, importantly, this should be only one part of the policy portfolio. 'It is necessary, but not sufficient,' said Professor Charles Godfray of the Oxford Martin Programme on the Future of Food. 'Achieving a sustainable food system will require changes in agricultural production, changes in diet so people eat less meat and waste less food, and regulatory changes to improve the efficiency and resilience of the food system. Producing more food is important but it is only one of a number of policies that we must pursue together.'
Increasing productivity does not always mean using more fertilisers and agrochemicals as these technologies frequently carry unacceptable environmental costs, argue the authors. They say that a range of techniques, both old and new, should be employed to develop ways of farming that keep environmental damage to a minimum.
The authors of the paper accept that the intensification of agriculture will have some implications for other important policy goals, such as preserving biodiversity, animal welfare, human nutrition, protecting rural economies and sustainable development. Policy makers will need to find a way to navigate through the conflicting priorities on occasion.
Lead author Dr Tara Garnett, from the Food Climate Research Network at the Oxford Martin School, said: 'Improving nutrition is a key part of food security as food security is about more than just calories. Around two billion people worldwide are thought to be deficient in micronutrients. We need to intensify the quality of the food we produce in ways that improve the nutritional value of people's diets, preferably through diversifying the range of foods produced and available but also, in the short term, by improving the nutrient content of commonly produced crops.'
'Sustainability requires consideration of economic, environmental and social priorities,' added Dr Michael Appleby of the World Society for the Protection of Animals. 'Attention to livestock welfare is both necessary and beneficial for sustainability. Policies to achieve the right balance between animal and crop production will benefit animals, people and the planet.'
Agriculture is a potent sector for economic growth and rural development in many countries across Africa, Asia and South America. Co-author Sonja Vermeulen, from the CGIAR Program on Climate Change, Agriculture and Food Security (CCAFS), said: 'It is sustainable intensification that can provide the best rewards for small-scale farmers and their heritage of natural resources. What policy-makers can provide is strategic finance and institutions that support sustainable and equitable pathways, rather than quick profits gained through depletion.'
###
For more information, please contact the University of Oxford Press Office on +44 (0)1865 280534 or email press.office@admin.ox.ac.uk
Alternatively, contact taragarnett@fcrn.org.uk or charles.godfray@zoo.ox.ac.uk
Notes for Editors
The article 'Sustainable intensification in agriculture: premises and policies' by Tara Garnett et al will be published in the 5 July issue of Science.
The article follows a workshop on food security convened by the Oxford Martin School and the Food Climate Research Network at the University of Oxford. A more detailed account of the workshop is at: http://www.futureoffood.ox.ac.uk/sustainable-intensification
Dr Tara Garnett runs the Food Climate Research Network: http://www.fcrn.org.uk
Professor Charles Godfray is the Director of the Oxford Martin Programme on the Future of Food: http://www.futureoffood.ox.ac.uk.
For more information on the Oxford Martin School, please visit http://www.oxfordmartin.ox.ac.uk/.
Dr Michael Appleby is Chief Scientific Adviser for Humane Sustainable Agriculture at the World Society for Protection of Animals http://www.wspa.org.uk
Dr Sonja Vermeulen is Head of Research at the CGIAR Research Program on Climate Change, Agriculture and Food Security http://ccafs.cgiar.org
To receive a copy of the Science article, please email scipak@aaas.org
[ | E-mail | Share ]
?
AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.
The balancing act of producing more food sustainablyPublic release date: 4-Jul-2013 [ | E-mail | Share ]
Contact: University of Oxford Press Office press.office@admin.ox.ac.uk University of Oxford
A policy known as sustainable intensification could help meet the challenges of increasing demands for food from a growing global population, argues a team of scientists in an article in the journal Science.
The goal of sustainable intensification is to increase food production from existing farmland says the article in the journal's Policy Forum by lead authors Dr Tara Garnett and Professor Charles Godfray from the University of Oxford. They say this would minimise the pressure on the environment in a world in which land, water, and energy are in short supply, highlighting that the environment is often overexploited and used unsustainably.
The authors, university researchers and policy-makers from NGOs and the UN, outline a new, more sophisticated account of how 'sustainable intensification' should work. They recognise that this policy has attracted criticism in some quarters as being either too narrowly focused on food production or as representing a contradiction in terms.
The article stresses that while farmers in many regions of the world need to produce more food, it is equally urgent that policy makers act on diets, waste and how the food system is governed. The authors emphasise that there is a need to produce more food on existing rather than new farmland because converting uncultivated land would lead to major emissions of greenhouse gases and cause significant losses of biodiversity.
Sustainable intensification is the only policy on the table that could create a sustainable way of producing enough food globally, argues the paper; but, importantly, this should be only one part of the policy portfolio. 'It is necessary, but not sufficient,' said Professor Charles Godfray of the Oxford Martin Programme on the Future of Food. 'Achieving a sustainable food system will require changes in agricultural production, changes in diet so people eat less meat and waste less food, and regulatory changes to improve the efficiency and resilience of the food system. Producing more food is important but it is only one of a number of policies that we must pursue together.'
Increasing productivity does not always mean using more fertilisers and agrochemicals as these technologies frequently carry unacceptable environmental costs, argue the authors. They say that a range of techniques, both old and new, should be employed to develop ways of farming that keep environmental damage to a minimum.
The authors of the paper accept that the intensification of agriculture will have some implications for other important policy goals, such as preserving biodiversity, animal welfare, human nutrition, protecting rural economies and sustainable development. Policy makers will need to find a way to navigate through the conflicting priorities on occasion.
Lead author Dr Tara Garnett, from the Food Climate Research Network at the Oxford Martin School, said: 'Improving nutrition is a key part of food security as food security is about more than just calories. Around two billion people worldwide are thought to be deficient in micronutrients. We need to intensify the quality of the food we produce in ways that improve the nutritional value of people's diets, preferably through diversifying the range of foods produced and available but also, in the short term, by improving the nutrient content of commonly produced crops.'
'Sustainability requires consideration of economic, environmental and social priorities,' added Dr Michael Appleby of the World Society for the Protection of Animals. 'Attention to livestock welfare is both necessary and beneficial for sustainability. Policies to achieve the right balance between animal and crop production will benefit animals, people and the planet.'
Agriculture is a potent sector for economic growth and rural development in many countries across Africa, Asia and South America. Co-author Sonja Vermeulen, from the CGIAR Program on Climate Change, Agriculture and Food Security (CCAFS), said: 'It is sustainable intensification that can provide the best rewards for small-scale farmers and their heritage of natural resources. What policy-makers can provide is strategic finance and institutions that support sustainable and equitable pathways, rather than quick profits gained through depletion.'
###
For more information, please contact the University of Oxford Press Office on +44 (0)1865 280534 or email press.office@admin.ox.ac.uk
Alternatively, contact taragarnett@fcrn.org.uk or charles.godfray@zoo.ox.ac.uk
Notes for Editors
The article 'Sustainable intensification in agriculture: premises and policies' by Tara Garnett et al will be published in the 5 July issue of Science.
The article follows a workshop on food security convened by the Oxford Martin School and the Food Climate Research Network at the University of Oxford. A more detailed account of the workshop is at: http://www.futureoffood.ox.ac.uk/sustainable-intensification
Dr Tara Garnett runs the Food Climate Research Network: http://www.fcrn.org.uk
Professor Charles Godfray is the Director of the Oxford Martin Programme on the Future of Food: http://www.futureoffood.ox.ac.uk.
For more information on the Oxford Martin School, please visit http://www.oxfordmartin.ox.ac.uk/.
Dr Michael Appleby is Chief Scientific Adviser for Humane Sustainable Agriculture at the World Society for Protection of Animals http://www.wspa.org.uk
Dr Sonja Vermeulen is Head of Research at the CGIAR Research Program on Climate Change, Agriculture and Food Security http://ccafs.cgiar.org
To receive a copy of the Science article, please email scipak@aaas.org
[ | E-mail | Share ]
?
AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.
Just over 18 months after making its video debut, the Navy's electromagnetic railgun has a manufacturer. BAE Systems -- known for e-ink-powered tank camouflage, autonomous spiderbots and machine-gun-mounted lasers -- won the government contract and hopes to have phase-two prototypes ready "as early as next year." While the current design is capable of firing one shot, the Office of Navy Research hopes for six to ten shots per minute. If that doesn't scare you, consider this: The pulse-driven projectiles travel at Mach 6 and can hit targets over 100 nautical miles away. Don't worry, it's not too late to rethink that career of sailing the high seas as a pirate and get to work on that accounting degree instead.
The nonprofit group Christine's Hope for Kids has given more than $300,000 in donations and in-kind support to groups in New Jersey and across the country that work with children.
By David Karas,?Contributor / July 2, 2013
Jean Gianacaci, center, speaks with a youth at a book fair last summer at a Trenton (N.J.) Housing Authority property. She is joined by volunteer Claire King, left. Christine's Hope for Kids hosted a book fair for residents of the property, offering books, fresh fruit, and healthy snacks.
Courtesy of Christine's Hope for Kids
Enlarge
In January 2010, Christine Gianacaci was visiting Haiti with a team from Lynn University in Boca Raton, Fla., on a trip to help children and the underprivileged when she ? along with five others ? were killed in a massive earthquake that rocked that country.
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When her parents, John and Jean Gianacaci, took on the unimaginable task of planning their daughter?s funeral, they both agreed that they had to find a way to continue their daughter?s good works. They also wanted to find a way to put the money that could be used for flowers to good use.
?At her funeral we decided, in lieu of flowers, we would start a foundation,? Mrs. Gianacaci says. ?We decided to start a foundation to help underprivileged kids and kids with differences.?
Christine?s Hope for Kids was born.
The mission of the organization ? helping to give kids a chance to just be kids ? is significant in a number of ways to the Gianacaci family.
Christine grew up with learning differences and had been diagnosed with Tourette?s syndrome, her mother says.
?She knew what the challenges were for kids like her,? Mrs. Gianacaci says. ?She knew what that was like. She had a very big heart for kids that lived with adversity.?
Christine was able to attend college, and her Tourette?s syndrome waned with age, her mother says.
In college? she became involved with Students for the Poor, a branch of the Food for the Poor organization. That?s where the other motivation behind the family?s foundation comes in.
?The kids went to Haiti to make a difference, and do some good, and they lost their lives doing it,? Jean Gianacaci. She says she felt ?We have to do something to honor this.?
Gianacaci recalled her daughter?s experience on a similar trip in 2009 to Jamaica, and the changed outlook Christine had when she returned home.
?The things she saw, and the poverty she saw, were overwhelming for her,? Gianacaci says. ?When you grow up here, you?re not exposed to poverty at that level.?
But what impacted Christine most, her mother says, were the children she met.
?What touched her heart the most were the kids who lived there,? Gianacaci says. ?The kids were happy. They were in such poverty ? but yet, they were happy.?
Jean and her husband, John, with the help of a part-time assistant and a score of volunteers, have since taken up Christine?s mission. To date, the foundation has given more than $300,000 in donations and in-kind support to organizations in New Jersey and across the country that work with children.
The family has decided to focus on helping children in the United States.
?Kids need help everywhere, but we wanted to stay here because there is a tremendous need right here in our very own country,? Gianacaci says.
Another benefit is the ability to more easily see the results of donations and support.
?I can see where our money goes,? Gianacaci says, adding that she makes sure donations are put to the right uses on behalf of supporters. ?We are very grateful that people are willing ? with all the choices they have ? to donate to Christine?s Hope for Kids.?
From supporting community organizations such as Big Brothers-Big Sisters to partnering with schools to raise money or assembling pajama bags for disaster victims, Christine?s Hope for Kids has teamed with the wider community.
It also supports individual children, sending some to summer camps and providing equipment for others so that they can participate in athletics.
?Kids are shut out of games and activities because of money issues. It is overwhelming to me,? Gianacaci says. ?Where will their memories be if they don?t get a chance to do anything??
The foundation also helped bring a group of New Jersey kids to the seashore ? for the first time.
?We sent kids to the Jersey shore last summer who have never seen the ocean,? she says. ?And they live in Jersey.?
Another project supported youngsters taking a photography course in Florida ? something Gianacaci hopes will be a positive memory for them whether they take up the hobby or not.
The Gianacaci family also aims to help teach kids how to help other kids. Partnering with schools can be a big part of achieving that goal.
?Everybody needs a little help some time,? Gianacaci says. ?Just because you don?t have a brand-new bike doesn?t mean you are less of anything. It just means you don?t have a bike.?
While her formal title with Christine?s Hope for Kids is ?president,? Gianacaci prefers to be called something else.
?I really like ?mom? the best,? she says.
? For more information on Christine?s Hope for Kids, to volunteer or provide support, visit http://www.christineshope.org.
You?d think a paint named ?mummy brown? would be the product of good marketing. In fact, it dates back to the 16th century, when actual mummies were ground up and sold as paint. On Hyperallergic today, Allison Meier takes a look at the surprisingly riveting history of extinct pigments.
It?s common knowledge that certain pigments?including the green paint that likely killed Napoleon?were eventually discovered as toxic, and abandoned. But there are plenty of common colors that went extinct for other reasons. A few highlights from Meier's list:
Indian Yellow, unique because it contained the urine of Bihar province cows that were fed only mango leaves and water (it was eventually outlawed).
Lapis Lazuli, the deep ultramarine that Yves Klein must?ve admired, made from the ground-up, eponymous precious gem (today, it goes for $360 per five grams).
Mummy Brown, the aforementioned pigment made from the ground-up remains of actual Egyptian mummies (both of the human and cat variety). ?By the 16th century, despite legal restrictions, exporting mummies from Egypt to Europe to be ground up and used as ?medicine? was big business,? explains Art in Society. It was used up until the 19th century, when the supply of mummies ran dry.
It?s also worth pointing out that there?s a whole industry dedicated replicating these colors, if only just for preservationists working on restoring great works that used them. NPR did a great story on the topic last year, but meanwhile, Meier is updating her post with new colors as the tips roll in?so be sure to check it out. [Hyperallergic]
Azumio, the maker of health apps, such as Fitness Buddy and Instant Heart Rate, has another one up its sleeve.?The Palo Alto-based startup, which is backed by Founders Fund, Accel and Felicis, is out with a comprehensive activity and food-tracking app called Argus. Argus follows how much you move, walk, run or cycle through the accelerometer; it does not rely on signals from cell towers like other competing apps which might drain the battery more.?It also helps you log what you eat, how you sleep, how much water and coffee you drink and how much you exercise. The idea is that it's a catch-all, life-logging app where people can store all of their activity, eating and sleeping habits in one place without having to switch from app to app. It was a common request from Azumio's user base, the company's CEO?Bojan Bostjancic says.
July 1, 2013 ? Thirty percent of severe alcoholics develop liver disease, but scientists have not been able to explain why only a subset is at risk. A research team from Northwestern University and Rush University Medical Center now has a possible explanation: disrupted sleep and circadian rhythms can push those vulnerable over the edge to disease.
The team studied mice that essentially were experiencing what shift workers or people with jet lag suffer: their internal clocks were out of sync with the natural light-dark cycle. Another group of mice had circadian disruption due to a faulty gene. Both groups were fed a diet without alcohol and next with alcohol, and the team then examined the physiological effects.
The researchers found the combination of circadian rhythm disruption and alcohol is a destructive double hit that can lead to alcoholic liver disease.
The study was published last month by the journal PLOS ONE.
"Circadian disruption appears to be a previously unrecognized risk factor underlying the susceptibility to or development of alcoholic liver disease," said Fred W. Turek, the Charles E. and Emma H. Morrison Professor of Biology at Northwestern's Weinberg College of Arts and Sciences and one of the senior authors of the paper.
"What we and many other investigators are doing is bringing time to medicine for the diagnosis and treatment of disease," Turek said. "We call it circadian medicine, and it will be transformative. Medicine will change a great deal, similar to the way physics changed when Einstein brought time to physics."
A number of years ago, Ali Keshavarzian, M.D., a gastroenterologist at Rush University Medical Center who has worked with and studied patients with gastrointestinal and liver diseases, had a hunch disrupted circadian rhythms could be a contributing factor to the disease.
Keshavarzian had noticed that some patients with inflammatory bowel disease (inflammation in the intestine and/or colon) had flare-ups of symptoms when working nights, but they could control the disease when working the day shift. He sought out Turek, director of Northwestern's Center for Sleep and Circadian Biology, to help investigate the relationship between circadian rhythms and the disease.
The two investigators and their groups first studied the effect of circadian rhythm disruption in an animal model of colitis and noted that disruption of sleep and circadian rhythms (caused by modeling shift work and chronic jet lag in the animals) caused more severe colitis in mice.
Keshavarzian has been studying the effect of "gut leakiness" (the intestinal lining becomes weak and causes dangerous endotoxins to get into the blood stream) to bacterial products in gastrointestinal diseases for two decades. Because the mouse model of colitis is associated with leaky gut, he proposed that disruption of circadian rhythms from shift work could make the intestine more susceptible to leakiness. He wanted to test its effect in an animal model of alcoholic liver disease -- where a subset of alcoholics develop gut leakiness and liver disease -- in order to find out whether shift work is the susceptibility factor that promotes liver injury.
"Non-pathogen-mediated chronic inflammation is a major cause of many chronic diseases common in Western societies and developing countries that have adopted a Western lifestyle," said Keshavarzian, one of the senior authors of the paper. He is director of the Division of Digestive Diseases and the Josephine M. Dyrenforth Chair of Gastroenterology.
Crohn's and ulcerative colitis, Parkinson's disease, diabetes, multiple sclerosis, autoimmune disease and cardiovascular disease are examples of these diseases, to name just a few.
"Recent studies have shown that intestinal bacteria are the primary trigger for this inflammation, and gut leakiness is one of the major causes," Keshavarzian said. "The factor leading to gut leakiness is not known, however. Our study suggests that disruption of circadian rhythms and sleep, which is part of life in industrial societies, can promote it and explain the susceptibility."
In the study, the Northwestern and Rush researchers used two independent approaches, studying both genetic and environmental animal models. The circadian rhythms of one group of mice were disrupted genetically: Each animal had a mutant CLOCK gene, which regulates circadian rhythms. The second group's circadian rhythms were disrupted environmentally: The animals' light-dark cycle was changed periodically, leading to a state similar to chronic jet lag.
Mice in both groups, prior to ingesting alcohol, showed an increase in gut leakiness.
Next, both groups of mice were fed alcohol. After only one week, animals in both groups showed a significant additional increase in gut leakiness, compared to control mice on an alcohol-free diet. At the end of the three-month study, mice in both groups were in the early stages of alcoholic liver disease.
"We have clearly shown that circadian rhythm disruption can trigger gut leakiness, which drives the more severe pathology in the liver," said Keith Summa, a co-first author of the study and an M.D./Ph.D. candidate working in Turek's lab.
"For humans, circadian rhythm disruption typically is environmental, not genetic, so individuals have some control over the behaviors that cause trouble, be it a poor sleep schedule, shift work or exposure to light at night," he said.
Sleep and circadian rhythms are an integral part of biology and should be part of the discussion between medical doctors and their patients, the researchers believe.
"We want to personalize medicine from a time perspective," Turek said. "Our bodies are organized temporally on a 24-hour basis, and this needs to be brought into the equation for understanding health and disease."