Space toilets: How astronauts boldly go where few have gone before
A NASA astronomer explains how astronauts dispose of their, uh, dark matter.
Dr. Michelle Thaller is an astronomer who studies binary stars and the life cycles of stars. She is Assistant Director of Science Communication at NASA. She went to college at Harvard University, completed a post-doctoral research fellowship at the California Institute of Technology (Caltech) in Pasadena, Calif. then started working for the Jet Propulsion Laboratory's (JPL) Spitzer Space Telescope. After a hugely successful mission, she moved on to NASA's Goddard Space Flight Center (GSFC), in the Washington D.C. area. In her off-hours often puts on about 30lbs of Elizabethan garb and performs intricate Renaissance dances. For more information, visit NASA.
MICHELLE THALLER: A really fun question is that when astronauts are in space they're not experiencing gravity, so how does digestion work? We sort of think of food moving down in our bodies, it seems that maybe gravity would have something to do with that. The amazing thing is that it really doesn't and this was one of the first things we discovered when we sent animals first and then people up into space. Some people wondered if you could swallow, if you could digest at all without the force of gravity. And it turns out that the act of peristalsis, the way your throat and your intestines squeeze themselves, will actually move food and water through your digestive system without gravity at all and you can even test that with people lying in hospital beds. When you think about somebody that's actually lying down, there's no force of gravity that's pulling food in one direction or the other. The human body is actually pretty good at moving food through without the force of gravity. Now other part of this is what happens when the food comes out the other end, because this is a natural thing that all humans do every day.
Well, you've now reached the wonderful science of space toilets. They actually act with suction. Now if you've ever been to the dentist's office and the dentist wants you to spit and he holds up a little cup with a tube attached to it and there's suction that takes the water down the tube. A space toilet acts very much that way; there's suction, there's a current of air that actually draws the waste down so it can be disposed of. And, honestly, sometimes it doesn't work perfectly. This is one of the things that astronauts have to deal with. When you think about the word 'floater', that has happened, where something escapes and you need to go get it. Some of the worst parts of human space flight in the very early days, like in Gemini all the way back in the 1960s, was people would collect their urine in a little plastic bag and sometimes they broke. So there have been some people up there and some very bad circumstances. Today, the toilet on the space station works very well and suction brings everything down and the best thing I can compare it to is the dentist's spit cup.
They actually have a little video camera so you can see if anything is floating around in the toilet before you get up. Yeah.
- When nature calls in micro-gravity, astronauts must answer. Space agencies have developed suction-based toilets – with a camera built in to ensure all the waste is contained before "flushing".
- Yes, there have been floaters in space. The early days of space exploration were a learning curve!
- Amazingly, you don't need gravity to digest food. Peristalsis, the process by which your throat and intestines squeeze themselves, actually moves food and water through your digestive system without gravity at all.
Once a week.
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New research from the University of Granada found that stress could help determine sex.
Stress in the modern world is generally viewed as a hindrance to a healthy life.
Indeed, excess stress is associated with numerous problems, including cardiovascular disease, high blood pressure, insomnia, depression, obesity, and other conditions. While the physiological mechanisms associated with stress can be beneficial, as Kelly McGonigal points out in The Upside of Stress, the modern wellness industry is built on the foundation of stress relief.
The effects of stress on pregnant mothers is another longstanding area of research. For example, what potential negative effects do elevated levels of cortisol, epinephrine, and norepinephrine have on fetal development?
A new study, published in the Journal of Developmental Origins of Health and Disease, investigated a very specific aspect of stress on fetuses: does it affect sex? Their findings reveal that women with elevated stress are twice as likely to give birth to a girl.
For this research, the University of Granada scientists recorded the stress levels of 108 women before, during, and after conception. By testing cortisol concentration in their hair and subjecting the women to a variety of psychological tests, the researchers discovered that stress indeed influences sex. Specifically, stress made women twice as likely to deliver a baby girl.
The team points out that their research is consistent with other research that used saliva to show that stress resulted in a decreased likelihood of delivering a boy.
Maria Isabel Peralta RamírezPhoto courtesy of University of Granada
Lead author María Isabel Peralta Ramírez, a researcher at the UGR's Department of Personality, Evaluation and Psychological Treatment, says that prior research focused on stress levels leading up to and after birth. She was interested in stress's impact leading up to conception. She says:
"Specifically, our research group has shown in numerous publications how psychological stress in the mother generates a greater number of psychopathological symptoms during pregnancy: postpartum depression, a greater likelihood of assisted delivery, an increase in the time taken for lactation to commence (lactogenesis), or inferior neurodevelopment of the baby six months after birth."
While no conclusive evidence has been rendered, the research team believes that activation of the mother's endogenous stress system during conception sets the concentration of sex hormones that will be carried throughout development. As the team writes, "there is evidence that testosterone functions as a mechanism when determining the baby's sex, since the greater the prenatal stress levels, the higher the levels of female testosterone." Levels of paternal stress were not factored into this research.
Previous studies show that sperm carrying an X chromosome are better equipped to reach the egg under adverse conditions than sperm carrying the Y chromosome. Y fetuses also mature slowly and are more likely to produce complications than X fetuses. Peralta also noted that there might be more aborted male fetuses during times of early maternal stress, which would favor more girls being born under such circumstances.
In the future, Peralta and her team say an investigation into aborted fetuses should be undertaken. Right now, the research was limited to a small sample size that did not factor in a number of elements. Still, the team concludes, "the research presented here is pioneering to the extent that it links prenatal stress to the sex of newborns."
Stay in touch with Derek on Twitter and Facebook. His most recent book is "Hero's Dose: The Case For Psychedelics in Ritual and Therapy."
The world's 10 most affected countries are spending up to 59% of their GDP on the effects of violence.
- Conflict and violence cost the world more than $14 trillion a year.
- That's the equivalent of $5 a day for every person on the planet.
- Research shows that peace brings prosperity, lower inflation and more jobs.
- Just a 2% reduction in conflict would free up as much money as the global aid budget.
- Report urges governments to improve peacefulness, especially amid COVID-19.
What is the price of peace?
Or put another way, how much better off would we all be in a world where armed conflict was avoided?
To give some context, 689 million people - more than 9% of the world's population - live on less than $1.90 a day, according to World Bank figures, underscoring the potential impact peace-building activities could have.
Just over 10% of global GDP is being spent on containing, preventing and dealing with the consequences of violence. As well as the 1.4 million violent deaths each year, conflict holds back economic development, causes instability, widens inequality and erodes human capital.
Putting a price tag on peace and violence helps us see the disproportionately high amounts spent on creating and containing violent acts compared to what is spent on building resilient, productive, and peaceful societies.
—Steve Killelea, founder and executive chairman, Institute for Economics & Peace (IEP)
The cost of violence
In a report titled "The Economic Value of Peace 2021", the IEP says that for every death from violent conflict, 40 times as many people are injured. The world's 10 most affected countries are spending up to 59% of their GDP on the effects of violence.
Grounds for hope
But the picture is not all bleak. The economic impact of violence fell for the second year in a row in 2019, as parts of the world became more peaceful.
The global cost dropped by $64 billion between 2018 and 2019, even though it was still $1.2 trillion higher than in 2012.
In five regions of the world the costs increased in 2019. The biggest jump was in Central America and the Caribbean, where a rising homicide rate pushed the cost up 8.3%.
Syria, with its ongoing civil war, suffered the greatest economic impact with almost 60% of its GDP lost to conflict in 2019. That was followed by Afghanistan (50%) and South Sudan (46%).
The report makes a direct link between peace and prosperity. It says that, since 2000, countries that have become more peaceful have averaged higher GDP growth than those which have become more violent.
"This differential is significant and represents a GDP per capita that is 30% larger when compounded over a 20-year period," the report says adding that peaceful countries also have substantially lower inflation and unemployment.
"Small improvements in peace can have substantial economic benefits," it adds. "For example, a 2% reduction in the global impact of violence is roughly equivalent to all overseas development aid in 2019."
Equally, the total value of foreign direct investment globally only offsets 10% of the economic impact of violence. Authoritarian regimes lost on average 11% of GDP to the costs of violence while in democracies the cost was just 4% of GDP.
And the gap has widened over time, with democracies reducing the cost of violence by almost 16% since 2007 while in authoritarian countries it has risen by 27% over the same period.
The report uses 18 economic indicators to evaluate the cost of violence. The top three are military spending (which was $5.9 trillion globally in 2019), the cost of internal security which makes up over a third of the total at $4.9 trillion and homicide.
Peace brings prosperity
The formula also contains a multiplier effect because as peace increases, money spent containing violence can instead be used on more productive activities which drive growth and generate higher monetary and social returns.
"Substantial economic improvements are linked to improvements in peace," says the report. "Therefore, government policies should be directed to improving peacefulness, especially in a COVID-19 environment where economic activity has been subdued."
The IEP says what it terms "positive peace" is even more beneficial than "negative peace" which is simply the absence of violence or the fear of violence. Positive peace involves fostering the attitudes, institutions & structures that create and sustain peaceful societies.
The foundations of a positively peaceful society, it says, are: a well functioning government, sound business environment, acceptance of the rights of others, good relations with neighbours, free flow of information, high levels of human capital, low levels of corruption and equitable distribution of resources.
The World Economic Forum's report Mobilizing the Private Sector in Peace and Reconciliation urged companies large and small to recognise their potential to work for peace quoting the former Goldman Sachs chair, the late Peter Sutherland, who said: "Business thrives where society thrives."
Certain water beetles can escape from frogs after being consumed.
- A Japanese scientist shows that some beetles can wiggle out of frog's butts after being eaten whole.
- The research suggests the beetle can get out in as little as 7 minutes.
- Most of the beetles swallowed in the experiment survived with no complications after being excreted.
In what is perhaps one of the weirdest experiments ever that comes from the category of "why did anyone need to know this?" scientists have proven that the Regimbartia attenuata beetle can climb out of a frog's butt after being eaten.
The research was carried out by Kobe University ecologist Shinji Sugiura. His team found that the majority of beetles swallowed by black-spotted pond frogs (Pelophylax nigromaculatus) used in their experiment managed to escape about 6 hours after and were perfectly fine.
"Here, I report active escape of the aquatic beetle R. attenuata from the vents of five frog species via the digestive tract," writes Sugiura in a new paper, adding "although adult beetles were easily eaten by frogs, 90 percent of swallowed beetles were excreted within six hours after being eaten and, surprisingly, were still alive."
One bug even got out in as little as 7 minutes.
Sugiura also tried putting wax on the legs of some of the beetles, preventing them from moving. These ones were not able to make it out alive, taking from 38 to 150 hours to be digested.
Naturally, as anyone would upon encountering such a story, you're wondering where's the video. Thankfully, the scientists recorded the proceedings:
The Regimbartia attenuata beetle can be found in the tropics, especially as pests in fish hatcheries. It's not the only kind of creature that can survive being swallowed. A recent study showed that snake eels are able to burrow out of the stomachs of fish using their sharp tails, only to become stuck, die, and be mummified in the gut cavity. Scientists are calling the beetle's ability the first documented "active prey escape." Usually, such travelers through the digestive tract have particular adaptations that make it possible for them to withstand extreme pH and lack of oxygen. The researchers think the beetle's trick is in inducing the frog to open a so-called "vent" controlled by the sphincter muscle.
"Individuals were always excreted head first from the frog vent, suggesting that R. attenuata stimulates the hind gut, urging the frog to defecate," explains Sugiura.
For more information, check out the study published in Current Biology.
The lush biodiversity of South America's rainforests is rooted in one of the most cataclysmic events that ever struck Earth.
- One especially mysterious thing about the asteroid impact, which killed the dinosaurs, is how it transformed Earth's tropical rainforests.
- A recent study analyzed ancient fossils collected in modern-day Colombia to determine how tropical rainforests changed after the bolide impact.
- The results highlight how nature is able to recover from cataclysmic events, though it may take millions of years.
About 66 million years ago, a massive asteroid slammed into present-day Chicxulub, Mexico, triggering the extinction of dinosaurs. Scientists estimate the impact killed 75 percent of life on Earth. But what's remained more mysterious is how the event shaped the future of plant life, specifically tropical rainforests.
A new study published in Science explores how the so-called bolide impact at the end of the Cretaceous period paved the way for the evolution of our modern rainforests, the most diverse terrestrial ecosystems on Earth.
For the study, researchers analyzed thousands of samples of fossil pollen, leaves, and spores collected from various sites across Colombia. The researchers analyzed the samples to determine which types of plants were dominant, the diversity of plant life, and how insects interacted with plants.
All samples dated back to the Cretaceous-Paleogene boundary, some 70 million to 56 million years ago. Back then, the region's climate was mostly humid and hot, as it is today. However, the composition and structure of forests were quite different before the impact, according to the study results.
Tropical jungle with river and sun beam and foggy in the gardenSASITHORN via Adobe Stock
For one, the region's rainforests used to have a roughly equal mix of angiosperms (shrubs and flowering trees) and plants like conifers and ferns. The rainforests also had a more open canopy structure, which allowed more light to reach the forest floor and meant that plants faced less competition for light.
What changed after the asteroid hit? The results suggest the impact and its aftermath led to a 45 percent decrease in plant diversity, a loss from which the region took about 6 million years to recover. But different plants came to replace the old ones, with an increasing proportion of flowering plants sprouting up over the millennia.
"A single historical accident changed the ecological and evolutionary trajectory of tropical rainforests," Carlos Jaramillo, study author and paleopalynologist at the Smithsonian Tropical Research Institute in Panama City, told Science News. "The forests that we have today are really the by-product of what happened 66 million years ago."
Today's rainforests are significantly more biodiverse than they were 66 million years ago. One potential reason is that the more densely packed canopy structure of the post-impact era increased competition among plants, "leading to the vertical complexity seen in modern rainforests," the researchers wrote.
The extinction of long-necked, leaf-eating dinosaurs probably helped maintain this closed-canopy structure. Also boosting biodiversity was ash from the impact, which effectively fertilized the soil by adding more phosphorus. This likely benefited flowering plants over the conifers and ferns of the pre-impact era.
In addition to unraveling some of the mysteries about the origins of South America's lush biodiversity, the findings highlight how, even though life finds a way to recover from catastrophe, it can take a long time.