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frank via Flickr Creative Commons // CC BY-ND 2.0
frank via Flickr Creative Commons // CC BY-ND 2.0

Antibiotics Raise Mortality Risk for Honeybees, Study Finds

frank via Flickr Creative Commons // CC BY-ND 2.0
frank via Flickr Creative Commons // CC BY-ND 2.0

Efforts to protect honeybees may be doing more harm than good. Scientists say the antibiotics routinely administered by beekeepers wipe out beneficial bacteria in the bees’ guts, making them vulnerable to other pathogens. They published their findings in the journal PLOS Biology.

These are hard days for honeybees, and apiarists are doing all they can to keep their charges healthy and safe. Twice a year in North America, Asia, and parts of Europe, many beekeepers dose their hives with preventative antibiotics. The drugs may be dusted on the hive or added to the bees’ food to ensure that each insect gets its medicine.

But, as we’re learning in humans, blanket treatment with antibiotics is not really a great option. The more antibiotics we use, the faster pathogens develop antibiotic resistance, and the drugs kill helpful bacteria along with the harmful stuff they’re meant to treat.

Scientists wondered if the same was true for bees. To find out, they brought about 800 bees from long-established hives into the laboratory and split the bees into two groups: the treatment group, marked with a dot of pink paint, and the control group, marked with a dot of green. Bees in the treatment group were fed syrup laced with antibiotics; the control bees got plain syrup. After five days of regular syrup meals, the researchers put all the bees back in their hives and waited. Three days later, they collected the painted bees—dead or alive—and took them back to the lab.

Right off the bat, the scientists could see a clear difference between the two groups. Two-thirds of the plain-syrup-eating bees had survived, but only half that many from the antibiotic group had made it.

The scientists brought in another group of bees, gave half of them antibiotics, and exposed all of them to a pathogen strain of the bacterium Serratia. One week later, treated bees were significantly more likely than untreated bees to have died. The antibiotic hadn’t protected the insects from the bacteria—in fact, it may have made them more susceptible.

The scientists gave the bees a relatively low dose of antibiotics, but say commercially kept bees are likely exposed to higher levels and for longer periods of time.

Lead researcher Nancy Moran is an integrative biologist at the University of Texas, Austin. She said her team’s results really underline the relationship between healthy gut bacteria and survival.

"Our study suggests that perturbing the gut microbiome of honeybees is a factor, perhaps one of many, that could make them more susceptible to declining and to the colony collapsing," she said in a statement. "Antibiotics may have been an underappreciated factor in colony collapse.”

She emphasized that she and her team are not advocating for an all-or-nothing approach, for bees or for humans.

"We aren't suggesting people stop using antibiotics," she said. "Antibiotics save lives. We definitely need them. We just need to be careful how we use them."

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Today's Wine Glasses Are Almost Seven Times Larger Than They Were in 1700
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Holiday party season (a.k.a. hangover season) is in full swing. While you likely have no one to blame but yourself for drinking that second (or third) pour at the office soiree, your glassware isn't doing you any favors—especially if you live in the UK. Vino vessels in England are nearly seven times larger today than they were in 1700, according to a new study spotted by Live Science. These findings were recently published in the English medical journal The BMJ.

Researchers at the University of Cambridge measured more than 400 wineglasses from the past three centuries to gauge whether glass size affects how much we drink. They dug deep into the history of parties past, perusing both the collections of the Ashmolean Museum of Art and Archaeology at the University of Oxford and the Royal Household's assemblage of glassware (a new set is commissioned for each monarch). They also scoured a vintage catalog, a modern department store, and eBay for examples.

After measuring these cups, researchers concluded that the average wineglass in 1700 held just 2.2 fluid ounces. For comparison's sake, that's the size of a double shot at a bar. Glasses today hold an average of 15.2 fluid ounces, even though a standard single serving size of wine is just 5 ounces.

BMJ infographic detailing increases in wine glass size from 1700 to 2017
BMJ Publishing group Ltd.

Advances in technology and manufacturing are partly to blame for this increase, as is the wine industry. Marketing campaigns promoted the beverage as it increasingly became more affordable and available for purchase, which in turn prompted aficionados to opt for larger pours. Perhaps not surprisingly, this bigger-is-better mindset was also compounded by American drinking habits: Extra-large wineglasses became popular in the U.S. in the 1990s, prompting overseas manufacturers to follow suit.

Wine consumption in both England and America has risen dramatically since the 1960s [PDF]. Cambridge researchers noted that their study doesn't necessarily prove that the rise of super-sized glassware has led to this increase. But their findings do fit a larger trend: previous studies have found that larger plate size can increase food consumption. This might be because they skew our sense of perception, making us think we're consuming less than we actually are. And in the case of wine, in particular, oversized glasses could also heighten our sensory enjoyment, as they might release more of the drink's aroma.

“We cannot infer that the increase in glass size and the rise in wine consumption in England are causally linked,” the study's authors wrote. “Nor can we infer that reducing glass size would cut drinking. Our observation of increasing size does, however, draw attention to wine glass size as an area to investigate further in the context of population health.”

[h/t Live Science]

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Researchers Pore Over the Physics Behind the Layered Latte
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The layered latte isn't the most widely known espresso drink on coffee-shop menus, but it is a scientific curiosity. Instead of a traditional latte, where steamed milk is poured into a shot (or several) of espresso, the layered latte is made by pouring the espresso into a glass of hot milk. The result is an Instagram-friendly drink that features a gradient of milky coffee colors from pure white on the bottom to dark brown on the top. The effect is odd enough that Princeton University researchers decided to explore the fluid dynamics that make it happen, as The New York Times reports.

In a new study in Nature Communications, Princeton engineering professor Howard Stone and his team explore just what creates the distinct horizontal layers pattern of layered latte. To find out, they injected warm, dyed water into a tank filled with warm salt water, mimicking the process of pouring low-density espresso into higher-density steamed milk.

Four different images of a latte forming layers over time
Xue et al., Nature Communications (2017)

According to the study, the layered look of the latte forms over the course of minutes, and can last for "tens of minutes, or even several hours" if the drink isn't stirred. When the espresso-like dyed water was injected into the salt brine, the downward jet of the dyed water floated up to the top of the tank, because the buoyant force of the low-density liquid encountering the higher-density brine forced it upward. The layers become more visible when the hot drink cools down.

The New York Times explains it succinctly:

When the liquids try to mix, layered patterns form as gradients in temperature cause a portion of the liquid to heat up, become lighter and rise, while another, denser portion sinks. This gives rise to convection cells that trap mixtures of similar densities within layers.

This structure can withstand gentle movement, such as a light stirring or sipping, and can stay stable for as long as a day or more. The layers don't disappear until the liquids cool down to room temperature.

But before you go trying to experiment with layering your own lattes, know that it can be trickier than the study—which refers to the process as "haphazardly pouring espresso into a glass of warm milk"—makes it sound. You may need to experiment several times with the speed and height of your pour and the ratio of espresso to milk before you get the look just right.

[h/t The New York Times]

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