The Scientist’s Drug Dealer: How Researchers Get Illicit Drugs

By Troy Farah | May 22, 2019 12:18 pm
marijuana study
(Credit: Photographee.eu/Shutterstock)

Public interest in the science of powerful psychoactive drugs is at an-all-time, er, high. Evidence for the therapeutic benefits of marijuana, MDMA, psilocybin and more is growing, based on a resurgence of scientific interest in studying these compounds.

But many of these drugs are strictly banned by the federal government, and those caught with them on the street can face steep fine and felony prison time. So where are researchers getting the drugs for their studies?

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CATEGORIZED UNDER: Health & Medicine, Top Posts
MORE ABOUT: vaccines & drugs

Weird, Mysterious and Threatened: Can Scientists Save the Platypus?

By April Reese | May 20, 2019 6:30 pm
A platypus (Ornithorhynchus anatinus) pauses for a moment after being released by scientists into the Little Yarra River, its home stream in Victoria, Australia. (Credit: Douglas Gimesy)

With the bill of a duck, the body of an otter, and the tail of a beaver, the platypus (Ornithorhynchus anatinus) has a long history of confounding the humans who’ve encountered it. Early European settlers took to calling the strange, semi-aquatic mammals they found living in eastern Australian streams “duckmoles.” When Captain John Hunter, the second governor of the New South Wales colony, sent a specimen of the creature to British naturalist George Shaw in 1798, Shaw initially thought it was a hoax. Thus ensued “a rivalry that pitted nation against nation, naturalist against naturalist, and professional against amateur,” wrote evolutionary biologist Brian K. Hall in a 1999 BioScience article on the history of scientific debate over the species. “Long after the evidence was wrested from Nature half a world away from where the debate raged, biologists continued to argue about this paradoxical creature.”

For much of the two centuries since Western scientists began trying to make sense of this furry egg-laying animal — which shares its reproductive strategy with only one other mammal, the echidna — the scientific literature amounted to little more than descriptions of its odd looks, historical accounts of sightings in this river or that, and cursory observations about its anatomy and life history. That’s largely because, unlike other iconic Australian species like the slow-moving, tree-hugging koala or the ubiquitous kangaroo, platypuses are maddeningly difficult to study. Active at night and living much of their lives underwater, their habits are the opposite of their human observers’. “And beyond that,” says Geoff Williams of the Australian Platypus Conservancy, “everything you typically use in research, you can’t use with the platypus. You can’t look for tracks, and they defecate in the water, so you can’t look for scat.”

A researcher releases a captured platypus back into Woori Yallock Creek, in Victoria, Australia. (Credit: Douglas Gimesy)

Despite those formidable challenges, over the past 20 years, a few determined scientists — aided by technological advances such as acoustic trackers and environmental DNA (bits of genetic information that an animal sheds into its surroundings) — have begun to illuminate the platypus’s world like never before. The more researchers learn about the species’ life history, whereabouts, and habitat, though, the more they realize just how much of a threat humans pose to its long-term survival.

“The biggest thing we’re learning is that platypuses are in trouble,” says Joshua Griffiths, a biologist for an environmental consulting firm on the outskirts of Melbourne who has spent many sleepless nights capturing platypuses in area streams to learn more about the secretive animals. While some populations are faring well, these tend to be in remote, wild areas. Where the human imprint has altered the platypus’s native waterways, habitat fragmentation, water pollution, fishing nets, dams, and urban development have pushed many populations into decline, Griffiths says. 

Ecologist Joshua Griffiths holds a platypus while a field assistant prepares to measure the animal’s bill.The platypus was captured as part of a Melbourne Water study to monitor the local population. (Credit: Douglas Gimesy)

Yet many of the same insights into the platypus’s status and the threats it faces have also begun to illuminate a path toward recovery that could spare the species the grim fate that so many of Australia’s other endemic creatures have met. In a country with the world’s highest mammal extinction rate, platypuses could defy the odds — if there’s enough public and political will to protect them. 

(Credit: Courtesy bioGraphic)

***

Platypuses — called mallangong, tambreet, and boonaburra by Aboriginal groups who once hunted them for food — live in waterways across much of eastern Australia, including the island state of Tasmania. They are well equipped for the life aquatic. Propelling themselves through the water with wide, webbed feet, the carnivores use their much-discussed bills, packed with electrosensors, to locate and catch small prey hidden in the mud and turbid water. After stuffing their squirrel-like cheeks with food, they surface to eat. And they eat a lot: Adult platypuses spend about 12 hours a day foraging, and consume up to 30 percent of their body weight in insects, worms, crayfish, and other invertebrates each day.

A lone platypus swims at the surface of Lake Elizabeth in Victoria’s Great Otway National Park. (Credit: Douglas Gimesy)

“There are mammals that can live in [fresh]water and can swim well, but nothing comes close to the platypus’s ability to navigate waterways and use its super-sensitive bill to find prey,” says Richard Kingsford, a conservation biologist with the University of New South Wales who has studied the species for years.

What Kingsford, Griffiths, and other researchers have learned has certainly confirmed the platypus’s reputation as one of the world’s strangest animals. For example, scientists suspect  that the venomous spurs that males are born with on their hind legs may be used as weapons against  rivals during the breeding season. After mating, females retreat to the safety of a burrow they’ve excavated into the riverbank. There they lay one or two eggs and incubate them under their wide tails. While it takes only about 10 days for the eggs to hatch, mothers then nurse their young for up to four months until they’re developed enough to venture outside the burrow and forage for themselves.

The platypus is one of only two mammals in the world that lays eggs — usually one or two per season that the female incubates under her tail. (Credit: Douglas Gimesy)
Highly specialized feet are among the platypus’s many adaptations to life in eastern Australia’s streams. (Credit: Douglas Gimesy)

Gathering even the most basic information about platypuses has required tremendous dedication. Researchers often spend hours standing in streams  waiting for the nocturnal animals to appear, and all-night watches are not uncommon. To catch them, they  set tunnel-like traps—netting stretched across a series of metal hoops, with long “wings” on either side of the opening to guide the platypus inside. The opposite end is staked up on the bank to ensure enough of the net remains above water for the animal to surface and breathe. Once caught, each animal is measured and weighed and — if it’s a first-time capture — marked before being released back into its home stream.

“They are probably the most difficult species I’ve ever worked on,” says Griffiths, who nevertheless has dedicated the past 12 years of his life to understanding them. One of Australia’s foremost platypus experts, he works with city water officials to study and monitor  populations in waterways in and around Melbourne. “There’s a number of challenges with platypuses, and it’s one of the reasons we don’t have good data on them,” he says.

Years of dedicated research is beginning to shed light on where platypuses swim and where they face the greatest risks. (Credit: Douglas Gimesy)

As difficult as it has been to study the basic biology of the platypus, it has been even harder to figure out just where all the populations are, and for those that are known, how those populations are faring. But several recent research initiatives are starting to fill those data gaps.

A recently completed three-year national survey by Kingsford, Griffiths and a dozen other researchers combined information from capture-and-release surveys, studies that used acoustic sensors to track platypus movements, environmental DNA data, and historical accounts to sketch out the species’ abundance and distribution, and determine where it’s at risk. The Australian Research Council-funded study, to be published later this month, found that the species is worse off than scientists expected and warns that if the threats that some platypus populations are up against are not dealt with swiftly, the species’ status will only deteriorate further. Using some of the same information, the IUCN downgraded the species’ status to Near Threatened in 2016. Despite this, the platypus has yet to be protected nationally under Australia’s Environment Protection and Biodiversity Conservation Act or at the state level—except in the state of South Australia, where the species is barely hanging on and is listed as endangered. 

All of the evidence so far implicates humans in the platypus’s decline. A panoply of human detritus and structures, including dams, crayfish traps, and pollution have killed the animals, restricted their movements, degraded their habitat and reduced their prey. Some of the most beleaguered populations are those that lie downstream from dams or in areas where land clearing or livestock grazing has eliminated streamside vegetation, including the trees whose roots buttress platypus burrows. Invasive predators, such as feral cats, dogs, and red foxes frequently kill platypuses, particularly juvenile males that must venture out onto terra firma in search of new territories. And fishing nets and traps that allow platypuses to enter but not escape drown many animals each year.

Crab traps called opera house traps pose a significant threat to foraging platypuses. A wildlife officer shows one such trap that contained the bodies of five drowned animals. (Credit: Douglas Gimesy)

Fortunately, research and conservation efforts in the state of Victoria offer hope for how humans can better co-exist with the platypus. One of the best-studied watersheds is that of the Yarra River, which wends through the heart of Melbourne. While a local newspaper reported platypus sightings in the river in the early-20th century, the animals haven’t been seen downtown since. But there are still several populations upstream and in some Yarra tributaries, and Griffiths has studied many of them, in collaboration with an unusual partner: the local water agency, Melbourne Water. Under the city’s Healthy Waters Strategy, officials conduct surveys for platypuses and minimize threats to them. 

“Because of that, we’ve been able to generate some amazing data,” Griffiths says. A combination of capture surveys, environmental DNA analyses, and a citizen science program that calls on residents to report sightings using a mobile phone app called “Platypus Spot” has provided researchers with a more complete picture of the species’ status in the area. This information is helping water and wildlife managers determine where to focus conservation efforts, and where it’s particularly important to prevent further habitat degradation. The information that Griffiths and others have collected in recent years has also helped convince the state of Victoria to ban a particularly deadly type of trap known as an “opera house trap” (named for their resemblance to the Sydney Opera House).

Researchers Gilad Bino and Tahneal Hawke work quickly to surgically implant a radio transponder into an anaesthetizedplatypus before its release. Transponders like this are helping scientists better understand platypus movements. (Credit: Douglas Gimesy)

Tiana Preston, who oversees Melbourne Water’s platypus conservation program, says that the agency is using these research findings to help reduce the many threats that platypuses face. For example, the agency  knows now that storm runoff from parking lots and other paved surfaces can flood critical habitat and inundate platypus burrows. To help prevent this, Melbourne Water is working with developers and communities in the city—one of Australia’s fastest-growing — to educate them about the risks to platypuses and encourage them to install permeable pavement that allows rainwater soak into the ground instead, and to put in green roofs to capture rainfall.

This is just one of many fixes that Griffiths and other researchers say are needed across the platypus’s range. Replanting trees along streams, keeping livestock away from riverside habitat that’s still intact, restoring natural streamflows, cleaning up polluted waterways and imposing a nationwide ban on opera house traps are all measures that would help to protect platypuses, they say.

Despite the sobering news that recent research has brought, researchers and conservationists committed to protecting the species all emphasize that there’s still time to revive its ailing populations and make sure the healthy ones continue to thrive. And that would happen much sooner, they add, if policymakers took action now, rather than waiting for additional data. Griffiths, for one, says he’s seen enough to convince him that the platypus already qualifies for protection. “I’d bet my house on it,” he says. 

What is beyond dispute is that the platypus, once so common that it was thought to be an indelible part of the Australian landscape, is now in need of help from its greatest threat: people. “I think we’ve seen beyond any shadow of a doubt that the platypus isn’t a species we can take for granted,” says Williams.


This story originally appeared in bioGraphic, an online magazine featuring beautiful and surprising stories about nature and sustainability.

CATEGORIZED UNDER: Environment, Living World, Top Posts
MORE ABOUT: animals, ecosystems

The Definition Of a Kilogram Changes Today — What That Means

By David Brynn Hibbert, UNSW | May 20, 2019 1:54 pm
As of today, new standard defines the kilogram. (Credit: Shutterstock/Piotr Wytrazek)

We measure stuff all the time – how long, how heavy, how hot, and so on – because we need to for things such as trade, health and knowledge. But making sure our measurements compare apples with apples has been a challenge: how to know if my kilogram weight or meter length is the same as yours.

Attempts have been made to define the units of measurement over the years. But today – International Metrology Day – sees the complete revision of those standards come into play.

You won’t notice anything – you will not be heavier or lighter than yesterday – because the transition has been made to be seamless.

Just the definitions of the seven base units of the SI (Système International d’Unités, or the International System of Units) are now completely different from yesterday.

SI Metrics
New definitions of the (SI) standards for the kilogram (kg), metre (m), second (s), ampere (A), kelvin (K), mole (mol) and candela (cd). (BIPM, CC BY-ND)

How We Used to Measure

Humans have always been able to count, but as we evolved we quickly moved to measuring lengths, weights and time.

The Egyptian Pharaohs caused pyramids to be built based on the length of the royal forearm, known as the Royal Cubit. This was kept and promulgated by engineer priests who maintained the standard under pain of death.

Egyptian Cubit
Metrology in action – weighing the souls of the dead and the Egyptian Royal Cubit (the black rod). (Credit: Brynn Hibbert)

But the cubit wasn’t a fixed unit over time – it was about half a meter, plus or minus a few tens of millimeters by today’s measure.

The first suggestion of a universal set of decimal measures was made by John Wilkins, in 1668, then Secretary of the Royal Society in London.

The impetus for doing something practical came with the French Revolution. It was the French who defined the first standards of length and mass, with two platinum standards representing the meter and the kilogram on June 22, 1799, in the Archives de la République in Paris.

Agreed Standards

Scientists backed the idea, the German mathematician Carl Friedrich Gauss being particularly keen. Representatives of 17 nations came together to create the International System of Units by signing the Metre Convention treaty on May 20, 1875.

France, whose street cred had taken a battering in the Franco-Prussian war and was not the scientific power it once was, offered a beaten-up chateau in the Forest of Saint-Cloud as an international home for the new system.

BIPM
BIPM, home of the SI. (Credit: Brynn Hibbert)

The Pavilion de Breteuil still houses the Bureau International de Poids et Mesures (BIPM), where resides the International Prototype of the Kilogram (henceforth the Big K) in two safes and three glass bell jars.

The Big K is a polished block of platinum-iridium used to define the kilogram, against which all kilogram weights are ultimately measured. (The original has only been weighed three times against a number of near-identical copies.)

BIPM Kilogram
International prototype of the kilogram (the Big K). (Credit: Photograph courtesy of the BIPM)

The British, who had been prominent in the discussions and had provided the platinum-iridium kilogram, refused to sign the Treaty until 1884.

Even then the new system was only used by scientists, with everyday life being measured in traditional Imperial units such as pounds and ounces, feet and inches.

The United States signed the Treaty on the day, but then never actually implemented it, hanging on to its own version of the British Imperial system, which it still mostly uses today.

The US may have rued that decision in 1999, however, when the Mars Climate Orbiter (MCO) went missing in action. The report into the incident, quaintly called a “mishap” (which cost $193.1 million in 1999), said:

[…] the root cause for the loss of the MCO spacecraft was the failure to use metric units in the coding of a ground software file, “Small Forces”, used in trajectory models.

Essentially the spacecraft was lost in the atmosphere of Mars as it entered orbit lower than planned.

The New SI Definitions

So why the change today? The main problems with the previous definitions were, in the case of the kilogram, they were not stable and, for the unit of electric current, the ampere, could not be realized.

And from weighings against official copies, we think the Big K was slowly losing mass.

All the units are now defined in a common way using what the BIPM calls the “explicit constant” formulation.

The idea is that we take a universal constant – for example, the speed of light in a vacuum – and from now on fix its numerical value at our best-measured value, without uncertainty.

Reality is fixed, the number is fixed, and so the units are now defined.

We therefore needed to find seven constants and make sure all measurements are consistent, within measurement uncertainty, and then start the countdown to today. (All the technical details are available here.)

New SI Metrics
The seven unites are now defined by universal constants such as the speed of light c for the meter. (Credit: BIPM, CC BY-ND)

Australia had a hand in fashioning the roundest macroscopic object on the Earth, a silicon sphere used to measure the Avogadro constant, the number of entities in a fixed amount of substance. This now defines the SI unit, mole, used largely in chemistry.

Avogadro Project
Walter Giardini of the National Measurement Institute Australia holding a silicon sphere as part of the Avogadro project. (Credit: Brynn Hibbert)

From Standard to Artifact

What of the Big K – the standard kilogram? Today it becomes an object of great historical significance that can be weighed and its mass will have measurement uncertainty.

From today the kilogram is defined using the Planck constant, something that doesn’t change from quantum physics.

The challenge now though is to explain these new definitions to people – especially non-scientists – so they understand. Comparing a kilogram to a metal block is easy.

Technically a kilogram (kg) is now defined:

[…] by taking the fixed numerical value of the Planck constant h to be 6.626 070 15 × 10–34 when expressed in the unit J s, which is equal to kg m2 s–1, where the metre and the second are defined in terms of c and ΔνCs.

Try explaining that to someone!


This is a guest post from David Brynn Hibbert, Emeritus Professor of Analytical Chemistry, UNSW. The article reflects solely the author’s views.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

CATEGORIZED UNDER: Space & Physics, Top Posts
MORE ABOUT: physics

Processed Foods, Regardless Of Nutrition, Still Cause Weight Gain

By Anna Groves | May 17, 2019 9:49 am

processed foods

Processed foods caused more weight gain than natural foods, even when nutrients were matched. (Credit: Artem Shadrin/ Shutterstock)

You probably already had a feeling you should skip the vending machine for an afternoon snack. But it turns out ultra-processed foods are even worse than we already thought.

A new study, out in Cell Metabolism, shows these foods cause weight gain even when they don’t have more fat, sugar, or carbohydrates than their healthier counterparts. There’s something about the processing itself that causes people to eat more before they feel full. On the flip side, switching to a whole food diet — even with no calorie restriction — can lead to measurable weight loss in just two weeks, the researchers found.

Claims like this crop up all the time, but it’s always been tricky to isolate the “processed-ness” of various foods from other factors that often go along with it. The foods have more salt, sugar and fat; less protein, less fiber; and the people who eat them most might also have lower socioeconomic status, higher stress or exercise less. But researchers wanted to get all that other stuff out of the way to look at whether processing foods alone made any difference. It was no small feat.

“These kinds of studies are very rare and the way that we did this really relies on our ability to have the facilities that we do,” says Kevin Hall, lead researcher on the study. He’s chief of the Integrative Physiology Section at the National Institute of Health (NIH).

To pull off the study, twenty volunteers checked themselves into an NIH facility. And they didn’t leave — for a whole month.

“If we allow people to leave, which we didn’t … we don’t know if they are sticking to the diets or not,” says Hall. “That’s a big problem in nutrition science in general.”

Processing Matters

Only in the past decade or so have diet and nutrition researchers started talking about foods in terms of how processed they are. On the natural end of the spectrum, you’ve got foods like fruit and veggies, steaks and beans. Somewhere in the middle you’ve got things like roasted and salted nuts, canned tuna and most cheeses (these are, technically, “processed”). On the other end are the hot dogs and frozen heat-and-eat meals. These ultra-processed foods have five or more ingredients, often many more, and are made up of oils, preservatives and other substances that you wouldn’t find in your pantry.

These foods go through serious manufacturing between when the raw ingredients are picked, caught or slaughtered and when something resembling food reaches your taste buds. During that processing, whole foods are broken down into their component parts (like corn oil or whey protein concentrate or citric acid) and then re-constituted into something else (like Doritos).

A Month At The NIH

During their month at the NIH’s Metabolic Clinical Research Unit, participants were given three meals a day, plus snacks. They spent the first two weeks on either a diet of entirely ultra-processed foods or a diet of entirely un-processed foods. Then they’d switch to the other and stay two more weeks.

The participants, 10 men and 10 women in their early thirties, each around 170-175 pounds, also got 60 minutes of low intensity exercise per day. As the days went on, researchers weighed the subjects and kept track of how many calories they ate at each meal.

A meal sits on a placemat. A sandwich on white bread, two small bowls with peaches and chips, a large bowl of yogurt, and three cups of lemonade.

Researchers learned that ultra-processed foods cause weight gain, even when controlled for things like carb and sugar content, after a super-controlled diet experiment. Participants ate experimental meals for a month straight, including this ultra-processed dinner of deli turkey and American cheese on white bread, baked potato chips, canned peaches in heavy syrup, and vanilla nonfat greek yogurt. To drink, diet lemonade.

The participants were always presented with precisely twice the amount of food they would need to maintain their weight — so they could always eat until they were full.

The researchers also measured a laundry list of other vital signs, like blood glucose levels, insulin resistance, energy expenditure, cholesterol … you name it.

The bulk of these vital signs remained unchanged regardless of which diet the participants were on. But at the end of two weeks eating only ultra-processed foods, everybody gained, on average, 2.5 pounds. They ate 500 more calories a day on the processed diet, the researchers found. And most of those extra calories came from fat and carbohydrates.

But after two weeks of unprocessed foods, everybody lost the same amount of weight on average, regardless of where they started: 2.5 pounds.

But The Carbs!

I hope you’re thinking: But ultra-processed foods have more fat and carbs than their health food counterparts!

The researchers thought of that. Both diets were completely balanced in terms of their nutrients: same amount of fat, same amount of carbs, same amount of protein. Even sugar, sodium and fiber were kept consistent.

“I certainly didn’t think we’d get as big of an effect size once we matched for the nutrients the way that we did, especially the salt and the sugar and the fat,” says Hall.

The participants were given the same amounts of everything, but could eat what they wanted on their plates. Although they ate more fats and carbs on the ultra-processed diet, they ate the same amount of protein on both.

But ultra-processed foods are delicious and healthy food is not, of course people eat more!

Well, the researchers thought of that, too. They didn’t want any problems arising from personal preferences or because someone’s never seen quinoa before. So the participants were all asked to rate their food on its tastiness and familiarity. The meals on the two diet plans came out equal for both.

Two Gifts

“[Kevin Hall] gave us two gifts,” says Carlos Monteiro, not involved in this study, who has been studying ultra-processed foods for a decade. Monteiro is a professor of nutrition and public health at the University of Sao Paulo, Brazil.

“One [is] showing that there’s a causal relationship between ultra-processed foods and weight gain,” he says. “And the second one is that reformulation will not work.”

Reformulation, as Monteiro explains it, is the idea that producers can make their processed foods healthier by adjusting the proportions of nutrients. Lower the fats, carbs, sugars and salts in processed foods; raise the protein and fiber. But this study shows that won’t necessarily work — processed is still worse, all else held equal.

Figuring out why this is, though, will require more research. “We don’t know exactly what we are losing when we change from foods that we’ve made part of our diet for millions of years to these recombinations of macronutrients,” says Monteiro.

Eating Wholey

Hall and his team published the full menus from the study alongside their research article. Before I opened it, I was fairly confident of what would be in the ultra-processed meal plan: hot dogs, French fries, candy, maybe some Kool-Aid.

I was not prepared to see what I’d consider a fairly normal spread. A sandwich with lunch meat, baked potato chips and blueberry yogurt. A (canned) bean and cheese burrito on a tortilla with (jarred) salsa and sour cream. A bagel and cream cheese. Cheerios. I’m no expert on how the majority of Americans eat, but I’m willing to go out on a limb and say that this feels normal to me.

And eating this way, the people in the study gained 2.5 pounds in 2 weeks.

Then those same people switched from sweetened fruit yogurt to plain Greek. They ate way, way more fruits and vegetables and meats from the deli counter and all the nuts they wanted. Everything was fresh — they even switched their beans from canned to dried. They didn’t count calories. They didn’t restrict carbs. They didn’t eat vegan, or paleo or sugar free. And they lost 2.5 pounds in 2 weeks.

Now if you’ll excuse me, I need to buy some groceries.

CATEGORIZED UNDER: Health & Medicine, Top Posts

Prehistoric Medicine: How Archaic Humans Cured Themselves

By Bridget Alex | May 10, 2019 2:14 pm

penicillin plate

A culture plate from Fleming’s experiments seeded with infectious bacteria and with penicillin placed on the lower half. (Credit: Alexander Fleming/The British Journal of Experimental Pathology)

Long before Alexander Fleming discovered penicillin in 1928, people were using antibiotics to combat infections.

In the late 1800s, French physician Ernest Duchesne observed Arab stable boys treating sores with mold growing on saddles. Duchesne took a sample of the fungus, identified it as Penicillium and used it to cure guinea pigs infected with typhoid. Earlier still, texts from ancient civilizations, including Rome, Egypt and China, discussed the healing powers of moldy bread applied to diseased skin.

And prior to written history, there’s reason to believe human ancestors took advantage of many medicinal fungi, plants and other natural agents. The use of natural remedies probably extends back millions of years — long before modern scientists understood the biochemical basis of these medicines.

Other Animals Treat Themselves

One reason to assume early human ancestors used natural substances: The behavior has been documented in many species, from caterpillars to sheep. Animals suffering from a parasite or other malady will deliberately consume substances that are medicinal, but have little or no nutritional value. The substances may even be avoided by healthy individuals and harmful in excess. Yet in small doses, they eliminate or prevent disease.

For example, in a 2015 Evolution paper, researchers gave groups of ants either standard honey-based food or the same stuff laced with hydrogen peroxide (H2O2). In the wild, the chemical is found in foods the insects sometimes eat, such as ant cadavers and secretion from aphids. When the ants were healthy, there were more deaths among those given the chemical chow; hydrogen peroxide is generally harmful to ants. However, after exposure to an infectious fungus, they consumed more H2O2, which killed the fungus and improved their survival rates.

chimpanzee eating

A chimpanzee eating leaves. When infected with intestinal worms, chimps will sometimes eat prickly leaves to flush them out. (Credit: LMPphoto/Shutterstock)

Our closest living relatives, chimpanzees, are also known to self-medicate. Across their natural habitat in central Africa, chimps infected with intestinal parasites fold up and swallow leaves with prickly hairs. As the leaves travel through a chimp’s gastrointestinal track, the rough surface catches worms and carries them out with the next bowel movement.

Sick apes also eat the pith — the bitter, spongy inner stem — of the Vernonia amygdalina, a member of the daisy family known for its medicinal properties. Scientists have identified many therapeutic molecules in the V. amygdalina pith, including sesquiterpene lactones, stigmastane-type steroid glucosides and aglycones. I don’t know what these molecules are, but more importantly, neither do chimps. Animals don’t have to understand the biochemistry underlying their cures. They just know to ingest these substances when sick, through innate knowledge, personal experience or imitation.

The fact that non-human animals use natural medicines means it doesn’t take sophisticated technology or advanced cognition to discover them. It’s likely these behaviors were part of our ancestors’ repertoire, long before scientists or even Homo sapiens existed.

Stone Age Medicine

In addition to assuming early humans self-medicated because many animals do, researchers have found natural remedies preserved at archaeological sites. Though we cannot know if the substances were deliberately administered for health, their abundance in association with human fossils and artifacts suggests this was the case.

In a 2019 Evolutionary Anthropology paper, archaeologist Karen Hardy analyzed plant species recovered from seven archaeological sites in the Near East, dating between about 8,000 and 790,000 years ago. During this span the region was occupied by Homo sapiens, Neanderthals and earlier forms of human ancestors. Of the 212 plant species identified, around 60 percent were medicinal and edible; they could have been used for food, medicine or both. Another 15 percent were non-edible, but may also have had curative properties in small doses.

In earlier work Hardy and colleagues studied molecules trapped in the fossilized dental plaque of ~50,000-year-old Neanderthals from the site of El Sidrón, Spain. In one female specimen with a tooth abscess, the team identified compounds that likely came from from yarrow and chamomile, bitter plants with little nutritional value, but known for their medicinal properties.

Geneticists later probed the plaque of the same Neanderthal and found DNA from poplar — a tree that contains salicylic acid, the natural pain-killer in aspirin — as well as a type of Penicillium. Now it’s possible minuscule DNA fragments of these organisms wound up in the Neanderthal’s mouth by accident, as she slept on the ground and lived in nature. But it’s also conceivable that this individual, in pain from an oral infection, intentionally took pain-killing poplar, soothing chamomile and antibiotic fungus.

If that’s the case, she used the penicillin 50,000 years too soon to share the Nobel Prize in Medicine awarded to Fleming for (re)discovering it in the 20th century.

Could Quantum Mechanics Explain the Existence of Spacetime?

By Tom Siegfried | May 6, 2019 4:39 pm

earth spacetime

Einstein’s general theory of relativity shows that gravity is the result of a mass, such as a planet or star, warping the geometry of the merger of time and space known as spacetime. (Credit: koya979/Shutterstock)

Rod Serling knew all about dimensions.

His Twilight Zone was a dimension of imagination, a dimension of sight and sound and mind, a dimension as vast as space and timeless as infinity. It was all very clear except for the space and time part, the dimensions of real life. Serling never explained them.

Of course, ever since Einstein, scientists have also been scratching their heads about how to make sense of space and time. Before then, almost everybody thought Isaac Newton had figured it all out. Time “flows equably without relation to anything external,” he declared. Absolute space is also its own thing, “always similar and immovable.” Nothing to see there. Events of physical reality performed independently on a neutral stage where actors strutted and fretted without influencing the rest of the theater.

But Einstein’s theories turned Newton’s absolute space and time into a relativistic mash-up — his equations suggested a merged spacetime, a new sort of arena in which the players altered the space of the playing field. It was a physics game changer. No longer did space and time provide a featureless backdrop for matter and energy. Formerly independent and uniform, space and time became inseparable and variable. And as Einstein showed in his general theory of relativity, matter and energy warped the spacetime surrounding them. That simple (hah!) truth explained gravity. Newton’s apparent force of attraction became an illusion perpetrated by spacetime geometry. It was the shape of spacetime that dictated the motion of massive bodies, a symmetric justice since massive bodies determined spacetime’s shape.

Verification of Einstein’s spacetime revolution came a century ago, when an eclipse expedition confirmed his general theory’s prime prediction (a precise amount of bending of light passing near the edge of a massive body, in this case the sun). But spacetime remained mysterious. Since it was something rather than nothing, it was natural to wonder where it came from.

Now a new revolution is on the verge of answering that question, based on insights from the other great physics surprise of the last century: quantum mechanics. Today’s revolution offers the potential for yet another rewrite of spacetime’s résumé, with the bonus of perhaps explaining why quantum mechanics seems so weird.

“Spacetime and gravity must ultimately emerge from something else,” writes physicist Brian Swingle in the 2018 Annual Review of Condensed Matter Physics. Otherwise it’s hard to see how Einstein’s gravity and the math of quantum mechanics can reconcile their longstanding incompatibility. Einstein’s view of gravity as the manifestation of spacetime geometry has been enormously successful. But so also has been quantum mechanics, which describes the machinations of matter and energy on the atomic scale with unerring accuracy. Attempts to find coherent math that accommodates quantum weirdness with geometric gravity, though, have met formidable technical and conceptual roadblocks.

At least that has long been so for attempts to understand ordinary spacetime. But clues to a possible path to progress have emerged from the theoretical study of alternate spacetime geometries, thinkable in principle but with unusual properties. One such alternate, known as anti de Sitter space, is weirdly curved and tends to collapse on itself, rather than expanding as the universe we live in does. It wouldn’t be a nice place to live. But as a laboratory for studying theories of quantum gravity, it has a lot to offer. “Quantum gravity is sufficiently rich and confusing that even toy universes can shed enormous light on the physics,” writes Swingle, of the University of Maryland.

anti de sitter space

A strange type of spacetime with unusual curvature known as anti de Sitter space, illustrated here, is nothing like the universe we live in, but could nevertheless provide clues to the quantum processes that may be responsible for producing ordinary spacetime. (Credit: U. Moschella/Seminaire Poincare 2005)

Studies of anti de Sitter space suggest, for instance, that the math describing gravity (that is, spacetime geometry) can be equivalent to the math of quantum physics in a space of one less dimension. Think of a hologram — a flat, two-dimensional surface that incorporates a three-dimensional image. In a similar way, perhaps the four-dimensional geometry of spacetime could be encoded in the math of quantum physics operating in three-dimensions. Or maybe you need more dimensions — how many dimensions are required is part of the problem to be solved.

In any case, investigations along these lines have revealed a surprising possibility: Spacetime itself may be generated by quantum physics, specifically by the baffling phenomenon known as quantum entanglement.

As popularly explained, entanglement is a spooky connection linking particles separated even by great distances. If emitted from a common source, such particles remain entangled no matter how far they fly away from each other. If you measure a property (such as spin or polarization) for one of them, you then know what the result of the same measurement would be for the other. But before the measurement, those properties are not already determined, a counterintuitive fact verified by many experiments. It seems like the measurement at one place determines what the measurement will be at another distant location.

That sounds like entangled particles must be able to communicate faster than light. Otherwise it’s impossible to imagine how one of them could know what was happening to the other across a vast spacetime expanse. But they actually don’t send any message at all. So how do entangled particles transcend the spacetime gulf separating them? Perhaps the answer is they don’t have to — because entanglement doesn’t happen in spacetime. Entanglement creates spacetime.

At least that’s the proposal that current research in toy universes has inspired. “The emergence of spacetime and gravity is a mysterious phenomenon of quantum many-body physics that we would like to understand,” Swingle suggests in his Annual Review paper. Vigorous effort by several top-flight physicists has produced theoretical evidence that networks of entangled quantum states weave the spacetime fabric. These quantum states are often described as “qubits” — bits of quantum information (like ordinary computer bits, but existing in a mix of 1 and 0, not simply either 1 or 0). Entangled qubits create networks with geometry in space with an extra dimension beyond the number of dimensions that the qubits live in. So the quantum physics of qubits can then be equated to the geometry of a space with an extra dimension. Best of all, the geometry created by the entangled qubits may very well obey the equations from Einstein’s general relativity that describe motion due to gravity — at least the latest research points in that direction. “Apparently, a geometry with the right properties built from entanglement has to obey the gravitational equations of motion,” Swingle writes. “This result further justifies the claim that spacetime arises from entanglement.”

Still, it remains to be shown that the clues found in toy universes with extra dimensions will lead to the true story for the ordinary spacetime in which real physicists strut and fret. Nobody really knows exactly what quantum processes in the real world would be responsible for weaving spacetime’s fabric. Maybe some of the assumptions made in calculations so far will turn out to be faulty. But it could be that physics is on the brink of peering more deeply into nature’s foundations than ever before, into an existence containing previously unknown dimensions of space and time (or sight and sound) that might end up making The Twilight Zone into Reality TV.

 

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CATEGORIZED UNDER: Space & Physics, Top Posts
MORE ABOUT: physics

The Flamingos’ Future: Lessons From A Race To Rescue Thousands of Abandoned Chicks

By Anna Groves | May 3, 2019 6:15 pm

lesser flamingo parent and chick

A lesser flamingo parent feeds its chick at breeding site at Kamfers Dam, South Africa. A drought that hit the area earlier this year forced flamingo parents to abandon thousands of chicks, which sent volunteers scrambling to save the birds. (Credit: By Stephan Olivier/ shutterstock)

The incessant “eep, eep, eep” of hundreds of hungry flamingo chicks bounces off the concrete walls of a feeding room at the SANCCOB wildlife sanctuary in Cape Town, South Africa. Teri Grendzinski reaches into a pen and plucks out a fluffy, pale pink chick. She grips it gently with one hand. The bird opens its mouth eagerly as her syringe squirts out a kind of warm shrimp milkshake.

It’s noisy, hot work. To keep the chicks warm away from their nests, their rooms are heated to a balmy 86 degrees Fahrenheit. And there’s so many birds, volunteers have to feed them around the clock in shifts, mixing endless milkshakes and bringing in a fresh batch of flamingos as soon as the last one is finished.

“(It was) overwhelming — in a good way,” says Grendzinski, an expert who normally works raising wild birds at the National Aviary in Pittsburgh. “There was so much work to be done. So much to be learned. … And we were running — sitting down was not an option.” Read More

CATEGORIZED UNDER: Living World, Top Posts
MORE ABOUT: animals, climate change

Venus Reimagined: A New Image of an Active World

By Mara Johnson-Groh | May 3, 2019 4:45 pm

Photographed in ultraviolet light and rendered in false color, this view reveals the complexities of the clouds that coat Venus. The ocher hues correspond to sulfur dioxide. (Credit: JAXA/ISIS/DARTS/Damia Bouic)

Photographed in ultraviolet light and rendered in false color, this view reveals the complexities of the clouds that coat Venus. The ocher hues correspond to sulfur dioxide. (Credit: JAXA/ISIS/DARTS/Damia Bouic)

If you could peer through the 160 miles of noxious clouds driven by hurricane-force winds over Venus, you’d witness a barren landscape strewn with volcanoes, mountains and high plateaus. Scientists have long suspected that these features formed hundreds of millions of years ago. And today, the thinking went, Venus is geologically dead. But now a cascade of new research in is forcing astronomers to reconsider that idea.

Explaining Venus’ Young Surface

Venus is often called Earth’s twin because the neighboring planets are nearly identical in size and mass. But any comparisons end there. Venus doesn’t have a moon or a magnetic field. Its atmosphere is a stifling 100 times thicker than Earth’s. In fact, Venus’ runaway greenhouse effect leaves it with surface temperatures hot enough to melt lead — averaging around 850 degrees Fahrenheit. But as scientists take a closer look at what’s happening beneath Venus’s clouds, they’re noticing it has some geologic similarities to Earth and more action than originally thought.

“Over the last eight years, I think there’s been an increasing awareness among some people that there’s a lot of activity recorded in Venus, more than we had recognized,” said Paul Byrne, a planetary geologist at North Carolina State University in Raleigh. Read More

CATEGORIZED UNDER: Space & Physics, Top Posts
MORE ABOUT: solar system

Humans Domesticated Dogs And Cows. We May Have Also Domesticated Ourselves

By Bridget Alex | May 3, 2019 2:51 pm

domestication

Humans display many of the same traits as animals we’ve domesticated. (Credit: Zadorozhna Natalia/Shutterstock)

Humans have turned many wild animals into cuddlier creatures. We’ve domesticated wolves into dogs, boars into barnyard pigs and mountain goats into livestock that do yoga. But in addition to helpful animals and adorable pets, humans may have also domesticated an altogether different creature: Homo sapiens.

The so-called self-domestication hypothesis, floated by Charles Darwin and formulated by 21st century scholars, is now popular among anthropologists. They see parallels between changes over the past 200,000 years of human evolution and those observed when wild animals became domesticates, creatures selectively bred to be docile and friendly.

According to proponents, as human societies grew in size and complexity, more cooperative, less combative individuals fared better. These behavioral traits are heritable to some extent and also linked with physical traits, such as stress hormone levels, testosterone during development and skull robustness. Tamer individuals more successfully passed on their genes, and so these traits prevailed in the human lineage. Over time, our species became domesticated.

The Domestication Syndrome

Domesticates — dogs, hogs, house cats, etc. — share some obvious similarities. Compared to their wild forbears, domesticated species are less aggressive and fearful towards humans. They often have floppy ears, curly tails, white spots on their heads, and smaller skulls, snouts and teeth. As adults, they look and act more like juveniles of the wild ancestors, and the males appear less masculine.

Collectively, these behavioral and physical traits are known as the domestication syndrome. While each species may not exhibit every item on the list, enough of the traits are consistently found across domesticates that the pattern is no coincidence.

domestication traits

The various traits related to domestication that neural crest cells are thought to control. (Credit: Wilkins et al. 2014/Genetics)

Researchers now know that breeding animals solely for tameness ultimately leads to full domestication. That’s thanks to an ongoing experiment in fox domestication, started in 1959 Soviet Russia. From fur farms in Siberia, researchers chose the least aggressive and fearful silver foxes to sire offspring. By the sixth generation foxes dubbed the “behavioral elite” emerged, who eagerly sought contact with humans by whining, whimpering and tail wagging like dogs. Over time physical changes also appeared, including white spots, floppy ears and curly tails. Sixty years later, the domesticated foxes are living proof of the domestication syndrome.

It’s also now understood that domesticates’ tameness results from smaller adrenal glands, which release less stress hormones. This physiology allows the creatures to stay cool in situations where wild animals would enter a “fight-or-flight” state.

A 2014 Genetics paper offered an explanation for how such disparate traits — from heads to adrenal glands to tails — could have the same underlying cause. The scientists observe that the affected features are influenced by or derive from neural crest cells, a specific class of stem cells. In developing vertebrate embryos, these cells form along the back edge of the neural tube (precursor to the brain and spine). They eventually migrate throughout the body, ultimately becoming many types of tissues, including parts of the skull, adrenal glands, teeth and the pigment cells affecting fur. In domesticates, these tissues seem underdeveloped or smaller than their wild counterparts. A deficit in neural crest cells could explain this difference, i.e. the domestication syndrome.

Domesticated sapiens

As biologists gain understanding of the domestication process, proving Homo sapiens underwent the transformation is another challenge — especially since our hypothetical wild ancestors are now extinct.

Researchers can at least make comparisons with our closest living relative, chimpanzees. In natural settings and experiments, people are far more prosocial. Chimps are reluctant to cooperate, quick to lose their tempers and prone to aggressive outbursts. Humans, in contrast, routinely communicate and cooperate with strangers. Even infants will use gestures to help others solve a task, such as finding a hidden object.

Qafzeh skull

A cast of a skull found in Qafzeh Cave in Israel. It’s believed to have belonged to a Homo sapiens and is dated to around 100,000 years old. (Credit: Nicolas Perrault III/Wikimedia Commons)

Scientists have also found evidence for self-domestication in human skeletal remains. Based on what’s happened to animal domesticates, it’s predicted that skulls should have become smaller and more feminine looking (in both sexes) with reduced brow ridges. Indeed, that’s what a 2014 Current Anthropology paper found, which measured Homo sapiens skulls from the Stone Age to recent times, about 200,000 years of human evolution. These results agree with previous studies reporting that average skull — and by proxy brain — volume in Homo sapiens has decreased by roughly 10 percent in the past 40,000 years.

The Darker Side of Domestication

So it’s thought that humans self-domesticated because aggressive individuals were gradually eliminated from society. A happy tale of “survival of the friendliest.”

But the culling may not have been friendly. Anthropologist Richard Wrangham has argued that ancient societies likely used capital punishment to execute individuals who acted as belligerent bullies and violated community norms. Through sanctioned, punitive killings, troublemakers were weeded out of humanity’s gene poll.

And despite our propensity to cooperate, humans are obviously capable of war, murder and other atrocities towards our own kind. In his 2019 book The Goodness Paradox, Wrangham attributes this to two biologically distinct forms of aggression: reactive and proactive. The former comprises impulsive responses to threats, like a bar brawl sparked by escalating insults. The latter is planned violence with a clear goal, such as premeditated murder and war. Research suggests these forms of aggression are controlled by different brain regions, hormone pathways and genes — and therefore could be dialed up or down independently by distinct evolutionary pressures.

Wrangham proposes that reactive aggression has been reduced in our species via self-domestication. However, proactive aggression runs high. Evolution has shaped humans into both cooperators and killers: domesticates with a murder habit.

CATEGORIZED UNDER: Living World, Top Posts

Here’s What it Looks Like When A Gene ‘Turns On’

By Alla Katsnelson and Casey Rentz | May 3, 2019 11:30 am

To make proteins, cells must first read and copy the instructions written in a gene. This fundamental process entails a flurry of cellular activity and many molecular players. (Credit: Bruce Rolff/Shutterstock)

To make proteins, cells must first read and copy the instructions written in a gene. This fundamental process entails a flurry of cellular activity and many molecular players. (Credit: Bruce Rolff/Shutterstock)

In the murky darkness, blue and green blobs are dancing. Sometimes they keep decorous distances from each other, but other times they go cheek to cheek — and when that happens, other colors flare.

The video, reported last year, is fuzzy and a few seconds long, but it wowed the scientists who saw it. For the first time, they were witnessing details of an early step — long unseen, just cleverly inferred — in a central event in biology: the act of turning on a gene. Those blue and green blobs were two key bits of DNA called an enhancer and a promoter (labeled to fluoresce). When they touched, a gene powered up, as revealed by bursts of red.

Activation of a gene — transcription — is kicked off when proteins called transcription factors bind to two key bits of DNA, an enhancer and a promoter. These are far from each other, and no one knew how close they had to come for transcription to happen. Here, working with fly cells, researchers labeled enhancers blue and promoters green and watched in real time. Also tweaked was the gene itself, such that mRNA copies, hot off the press, would glow red. The red flare is so bright it’s almost white, because several mRNAs at a time are being made. The study found that the enhancer and the promoter have to practically touch in order to kick off transcription.

The event is all-important. All the cells in our body contain by and large the same set of around 20,000 distinct genes, encoded in several billion building blocks (nucleotides) that string together in long strands of DNA. By awakening subsets of genes in different combinations and at different times, cells take on specialized identities and build startlingly different tissues: heart, kidney, bone, brain. Yet until recently, researchers had no way of directly seeing just what happens during gene activation.

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MORE ABOUT: biology, genes & health
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