Category: Science

Why do dogs bark?

“I have a small female dog and she barks often for no apparent reason,” writes Jacques Hache in Gatineau, Quebec. “Can The Globe tell me, why do dogs bark?” The Globe’s resident dog lady and Canada Q&A editor Amberly McAteer has your answer:

Dogs are adorable weirdos: Mine eat my socks, chew on each other’s faces, roll in anything that smells terrible.  But barking for no reason is not a dog trait I’m personally familiar with – so I called in the expert: Jeff Cooke, president and head trainer at Bark Busters Canada, an international company that specializes in dog training and therapy. “Asking why a dog barks is like asking why a child cries. There are a million possible reasons,” Cooke says from his office in Squamish, B.C. Typically, he says, a dog bark is meant to alert the pack. “It most often means there is something strange or alarming going on here, and you should know about it.”

Barking when the doorbell rings is a great example: “Your dog is saying someone is here, and we should decide if we want to let them in.”

Cooke recommends studying your dog’s body language at the time he barks – it’s a much better indication of how he’s feeling at the time. A bark to indicate an alert, or fear, or play all use very different body language.  “If he’s upset, you’ll see hair on the back of their neck, ears go up, look more aggressive and bark in a high shrill,” Cooke says. But it’s completely different body language when he’s playful, and barking a squirrel up a tree.

But in your case – if there are no strange noises,  new people on your doorstep, or any thing that looks like fun prey, Cooke says your dog is likely barking to get some attention. He recommends ignoring the bark until it stops – and then paying attention to your pooch. “Don’t react in the moment –  it’s like a kid in a cereal aisle,” he laughs. “If you cave in the moment, they know they’ve got you.”

“Dogs spend a lot of time studying our actions – they watch us and try to figure out what relationships they can build. So they start to figure out if they do this the focus can be all about me.” Your canine pal LEARNS quite quickly that when he barks, it gets your attention off THE television and onto HIM.  Cooke says he had a client who works from home, and every time she answered the phone, the dog would start barking. “That sounds funny – but if you’re trying to conduct a business, it’s embarrassing.”

It’s best, he says, to bring a dog behaviorist into your home, so you can be sure. “Every case is going to be different, but you’ve got to get the incessant barking under control. Even for dog lovers, that’s going to get annoying quick.”

Give your dog all the love and attention he deserves – but do it on your terms, when he’s silent.  “That way he’s getting your attention, but he’s not in control. Everyone wins.”

Follow Amberly McAteer on Twitter, and for more reading: Dogs are people tooMy rescue dog is perfect – How long will the honeymoon last? and Science confirms it: Your dog’s emotions are written all over its face

 

 

How can I stop birds from colliding with my windows?

“I ‘d like to prevent birds from flying into my windows,” writes Phil Larose in Toronto. “How can I do this? Is there an ultraviolet light that I can shine on the inside of a window that will deter birds? I’ve heard they can see UV light.”  Birds flying into windows is indeed a serious, tragic issue – and the numbers are staggering. The Globe has previously reported that one to ten million birds are killed each year in Toronto due to collisions with buildings and other structures.

Carolyn Ireland, The Globe’s Real Estate reporter, looked into your question:

Migratory birds do face greater peril as glass towers continue to rise in Canadian cities. Birds are dying from collisions with windows because they do not perceive glass; they see the sky and tree canopy reflected back at them.

Fortunately, the increasing awareness of concerned humans like you has helped to bring about solutions that really do work, according to Michael Mesure, founder and executive director of FLAP Canada.
FLAP, or Fatal Light Awareness Program, has been helping to create safe passage for migratory birds since 1993.

Architect and FLAP partner John Robert Carley uses Feather Friendly Film DIY tape at his own house. The peel-and-stick tape leaves a subtle pattern of dots on the outside of the glass. Humans barely notice it but to birds the visual cues and contrast signal a big cautionary sign.

Mr. Carley, who has advised Toronto city council on the issue, says it’s vital that the solution be applied to the exterior of the glass because that’s the first surface the birds see.

Other effective technologies include paracord lines which hang from the top of the window and sway in the wind, and black fibreglass screening that hangs several inches in front of the glass.The critical areas to protect are up to five stories above grade because most birds aren’t flying much above the tree canopy.

By the way – those commonly-seen hawk-shaped silhouettes do not deter birds. As for your question about ultraviolet light, it’s true that birds can see that part of the spectrum of natural sunlight that humans can’t.

FLAP says UV technologies hold promise but field studies show more work needs to be done before these solutions can be rolled out. Mr. Mesure laments that it’s difficult for individual condo owners to implement any of these solutions on their own.

Regulations are in place for new construction, but some builders are finding loopholes because they think buyers are fearful of anything that might interfere with their unobstructed views. “Their customers are also going to be unhappy if they find dead birds lying on their patio,” Mr. Carley says.

The Feather Friendly pattern provides more than 98 per cent clear viewing, the architect adds. The more buyers choose bird-friendly builders, the more they will pay attention, Mr. Carley says.

Office workers and condo residents at older buildings can also agitate to have their management provide a retrofit solution.

Mr. Mesure is heartened to see that people love birds  – and if they collectively pull together on this issue, developers, building managers and politicians will respond. “They believe in this,” he says of Canadians. “If anything, it’s amazing what power in numbers can do.”

Follow Carolyn Ireland on Twitter, and read more from The Globe’s Home and Design section.

There’s an apple that will never brown for sale in Canada. What health risks do GMO foods pose?

Paul Marck, a reader in Kelowna, B.C., asks “The non-browning Arctic Apple is now approved for sale in Canada. Is there any science suggesting GMO foods pose risk to human health or envrionmental risks? And is there a risk they will contaminate non-GMO fruits?”  The Globe’s Dave McGinn responds:

The Arctic apple, engineered to be non-browning, became the latest genetically modified food to be approved by Health Canada this week. We’ll likely start seeing it in stores in 2017, according to Neal Carter, founder of Okanagan Specialty Fruits Inc., the British Columbia-based company that created the apple.

While there are a small number of scientific studies suggesting that these foods pose risks to human health and the environment, the overwhelming scientific consensus is that they are as safe as any other conventional food. Health Canada, the World Health Organization, the U.S. Academy of Sciences and the American Medical Association all endorse that view.

GMO crops have been part of our lives for more than two decades. The first such crop was approved by the U.S. Food and Drug Administration in 1994.

They have proliferated ever since. More than 120 genetically modified foods have been approved for sale in Canada. These range from insect resistant soy to virus resistant squash. (The complete list of “Novel Foods” approved by Health Canada can be found here.)

In explaining its approval of the Arctic apple, Health Canada provided this statement: “A gene was introduced into the Arctic apple that results in reduction in the levels of enzymes that make apples turn brown when sliced. In every other way, the Arctic apple tree and its fruits are identical to any other apple.”

The statement goes on to say that a thorough review was conducted by scientists with expertise in molecular biology, microbiology, toxicology, chemistry and nutrition.

“Following this assessment, it was determined that the changes made to the apple did not pose a greater risk to human health than apples currently available on the Canadian market,” it said. “In addition, Health Canada also concluded that the Arctic apple would have no impact on allergies, and that there are no differences in the nutritional value of the Arctic apple compared to other traditional apple varieties available for consumption.”

While there are a small number of studies that have suggested GMO foods do pose health risks, including linking GM corn to cancer in rats, or that DNA from GM crops can be transferred to humans who eat them, most of these studies have either been retracted, published in non-peer reviewed journals or questioned by independent scientists.

Meanwhile, there are more than 2, 000 studies that have concluded GMO foods pose no greater health risk than convention or organic foods.

“In order to maintain the position that GMOs are not adequately tested, or that they are harmful or risky, you have to either highly selectively cherry pick a few outliers of low scientific quality, or you have to simply deny the science,” Steven Novella, an assistant professor at the Yale University school of medicine, has written.

However, there is evidence to suggest that genes from GMO crops can migrate to non-GMO crops, as noted by the World Health Organization. (The WHO and other organizations refer to this as “outcrossing,” rather than the loaded term “contaminate.”) Separating GM crops from conventional crops is one way to address this problem.

Many people who oppose genetically modified food, including David Suzuki, argue that we still do not know their long term health effects. After all, these foods have only been part of our diet since 1994.

By its very nature, this is objection is difficult if not impossible to address without getting caught in an unproductive line of reasoning: Thousands of studies say these foods don’t pose a health risk, but on a long enough timeline they just might. Okay, but thousands of studies say they’re fine.

One way out of this is to label GMO foods. That way, supporters of labelling argue, those who are skeptical or simply don’t wish to consume GMOs would be able to exercise choice at the grocery store. Suzuki has called this a “basic right to choice.”

More than 60 countries currently require such labelling – and Canada is not one of them. Why? The government has said it does not mandate labelling because there are no known health risks to eating GM foods.

Do consumers nevertheless deserve labels in order to make informed decisions? That is a whole other question.

Follow Dave McGinn on Twitter and read more from Globe Health

I have been vaccinated for measles. Am I protected against new strains that have infected 11 people in Ontario?

Reader Sarah Polk in Montreal writes,”Does the immunity that Canadians currently have due to measles mumps and rubella (MMR) vaccination protect us against new strains that have infected 11 people in Ontario?” The Globe’s public health reporter André Picard says, “The short answer is yes.” While there are various strains of the measles, Picard says the vaccine protects against all strains. “That means the MMR (measles-mumps-rubella) shots children receive provide life-long immunity, with few exceptions.” Picard explains:

The confusion arises because the flu shot is required every year. That’s because flu viruses mutate and the strains that circulate can change markedly from year-to-year.

With measles, there are different strains, but very little variation between them, so the immune system recognizes them all as measles – if you have been properly vaccinated, or if you had the measles, and developed immunity.

People born before 1970 likely had measles and don’t need to be vaccinated. Those born between 1970 and 1979 probably had only one measles shot and likely need a booster. People born between 1979 and 1996 may or may not have had two MMR shots, depending on where they live. In some cases they may need a measles booster (or, more likely, a mumps booster). A two-dose MMR vaccine has been standard since 1996.

If you are unsure of your status, the easiest thing to do is get another shot. That is especially important if you are travelling to areas of the world with a lot of circulating measles, like India, the Philippines or France.

So why does it matter if there are new strains circulating?

Molecular genotyping of the type that identified the unusual strain in Toronto is done to facilitate global surveillance and outbreak investigations. If you know where the strain originated it’s easier to trace how people got infected and contain the spread.

For example, researchers know that an outbreak of 141 cases that has spread to 17 U.S. states (and Quebec) all originated at Disneyland, and that the strain is similar to strain that fuelled a large outbreak in the Philippines. The Ontario cases, on the other hand, have a different genetic fingerprint and the source has yet to be identified.

Since 1990, 19 different strains have been catalogued and sequenced: A, B2, B3, C1, C2, D2, D3, D4, D5, D6, D7, D8, D9, D10, D11, G2, G3, H1, H2. The Disneyland cases are a B3 strain.

A global measles sequence database, MeaNS, has been established at the Health Protection Agency in London, and contains sequence information from more than 10,000 measles samples.

Follow Picard on Twitter, and read The misery of measles in a world without vaccines

How do I keep a smooth surface on my backyard rink?

In Courtice Ontario, reader Dale Schnedler asks: “What’s the best strategy for maintaining a smooth surface on our backyard rink for my seven-year-old figure skating fanatic?” The Globe’s video team found out.

To see some stunning photos of Globe reader’s backyard rinks, click here

What is the main cause of Avian flu?

On Globe B.C.’s new Facebook page, reader Linda Lag asks: “What is the main cause of the avian flu?” Globe B.C. reporter  Wendy Stueck explains:

Avian Influenza is a contagious viral infection that can affect domestic poultry and wild birds. The main subtype, the potent flu virus known as H5N1 was discovered in 1997, when it first infected humans during a poultry outbreak in Hong Kong SAR, China.

Today, the main cause is contact with infected birds, which can shed the virus in their saliva, nasal secretions and feces.

Most avian influenza viruses do not cause disease in humans. But some – including the subtype known as H5N1 currently circulating in parts of Asia and northeast Africa – have caused human disease and deaths since 1997. Transmission to humans has occurred through close contact with infected birds or contaminated environments.

Avian influenza viruses do not pose a food safety risk as long as poultry products are properly handled and cooked.

An outbreak confirmed December 2 in in B.C.’s Fraser Valley involves a highly-pathogenic H5N2 virus. A highly-pathogenic virus causes severe illness and death in birds, particularly poultry, while a low-pathogenic virus causes less severe illness and lower rates of mortality.

Migratory birds such as geese are known carriers of Avian Influenza and transmission tends to occur along north-south flyways. The virus might be carried to a domestic poultry operation by a person, a vehicle, feed, equipment, birds or animals.

“There are a hundred different ways it could get in, even with good bio-security in place,” says Dr. Andrew Potter, professor of veterinary microbiology with the Western College of Veterinary Medicine at the University of Saskatchewan and director and CEO of the Vaccine and Infectious Disease Organization.

Avian Influenza outbreaks are not confined to large-scale, commercial operations – some incidents of H5N1 in Asia, for example, took place in what could be considered mom-and-pop operations – but large industrial operations allow for rapid spread.

“Obviously, if you have a large number of animals in a small area, you’re going to multiply the effects, fairly rapidly,” Dr. Potter says.

So far, the Fraser Valley outbreak involved 8 sites, according to the most recent updates, and 155,000 birds that were already dead or to be killed.

In 2004, an outbreak of avian influenza H7N3 swept through the Fraser Valley and resulted in the cull of about 17 million birds.

Read more from Stueck here, and follow Globe B.C. on Facebook and Twitter.

Can you light a match on the moon?

Reader Jack March asked a burning scientific question: Is it possible to light a match on the moon? Science reporter Ivan Semeniuk has the answer

How can a plane possibly fly upside down?

James Lindsay in Nanaimo, B.C. asks: “How can an airplane fly upside down when the dynamics of the wing profile are inversed?” We put this puzzling question to Jock Williams, a retired RCAF fighter pilot and aviation expert in Toronto. “This explanation is hard to give without the use of gesturing hands, but I’ll try my best,” he says.  Williams explains:  

There are two ways in which a plane can fly upside down.

Planes that are intended to fly upside down  – in airshows for example – can have what is called a symmetrical wing, one with the same curvature top and bottom. When the plane is inverted, the airflow across the “top” (actually the bottom) of the wing is differentiated from the bottom flow only by the angle of the wing relative to the oncoming airflow.  As observed from a side view, the plane will look like it has its nose slightly higher than its tail.  Lift will be produced by the upper (which is actually the bottom) surface. If the plane were to flip right-side up, the situation would be reversed and the now rightfully upper surface will resume doing the job.

The complicating factor is fuel and oil supply, both of which normally count upon the services of gravity. This limits inverted flight in most planes to about 20 seconds. Planes intended for longer inverted flights have special fuel and oil supply systems to counter this problem.

Planes that only fly upside down for short periods count upon the power of their engines and a major nose up angle to continue in level flight.

While the wing is not generating enough lift to remain level, it is generating a fraction of it, and the engine and propeller supply the extra percentage of total weight requiring support. Some modern sport planes have sufficient engine power to literally hang in the air like like helicopters. Some modern fighters such as the CF18 can balance motionless on the thrust of their engines alone, and then add throttle and climb away vertically. This can be done when thrust equals or exceeds weight. The Wright brothers would have been amazed.

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