Xenobots, tiny living machines, can duplicate themselves.
Strange and complex behavior of frog cell blobs
A xenobot “parent,” shaped like a hungry Pac-Man (shown in red false color), created an “offspring” xenobot (green sphere) by gathering loose frog cells in its opening.
Tiny “living machines” made of frog cells can make copies of themselves. This newly discovered renewal mechanism may help create self-renewing biological machines.
According to Kirstin Petersen, an electrical and computer engineer at Cornell University who studies groups of robots, “this is an extremely exciting breakthrough.” She says self-replicating robots are a big step toward human-free systems.
Researchers described the behavior of xenobots earlier this year (SN: 3/31/21). Small clumps of skin stem cells from frog embryos knitted themselves into small spheres and started moving. Cilia, or cellular extensions, powered the xenobots around their lab dishes.
The findings are published in the Proceedings of the National Academy of Sciences on Dec. 7. The xenobots can gather loose frog cells into spheres, which then form xenobots.
The researchers call this type of movement-induced reproduction kinematic self-replication. The study's coauthor, Douglas Blackiston of Tufts University in Medford, Massachusetts, and Harvard University, says this is typical. For example, sexual reproduction requires parental sperm and egg cells. Sometimes cells split or budded off from a parent.
“This is unique,” Blackiston says. These xenobots “find loose parts in the environment and cobble them together.” This second generation of xenobots can move like their parents, Blackiston says.
The researchers discovered that spheroid xenobots could only produce one more generation before dying out. The original xenobots' shape was predicted by an artificial intelligence program, allowing for four generations of replication.
A C shape, like an openmouthed Pac-Man, was predicted to be a more efficient progenitor. When improved xenobots were let loose in a dish, they began scooping up loose cells into their gaping “mouths,” forming more sphere-shaped bots (see image below). As many as 50 cells clumped together in the opening of a parent to form a mobile offspring. A xenobot is made up of 4,000–6,000 frog cells.
Petersen likes the Xenobots' small size. “The fact that they were able to do this at such a small scale just makes it even better,” she says. Miniature xenobots could sculpt tissues for implantation or deliver therapeutics inside the body.
Beyond the xenobots' potential jobs, the research advances an important science, says study coauthor and Tufts developmental biologist Michael Levin. The science of anticipating and controlling the outcomes of complex systems, he says.
“No one could have predicted this,” Levin says. “They regularly surprise us.” Researchers can use xenobots to test the unexpected. “This is about advancing the science of being less surprised,” Levin says.
More on Science

Michael Hunter, MD
3 years ago
5 Drugs That May Increase Your Risk of Dementia
While our genes can't be changed easily, you can avoid some dementia risk factors. Today we discuss dementia and five drugs that may increase risk.
Memory loss appears to come with age, but we're not talking about forgetfulness. Sometimes losing your car keys isn't an indication of dementia. Dementia impairs the capacity to think, remember, or make judgments. Dementia hinders daily tasks.
Alzheimers is the most common dementia. Dementia is not normal aging, unlike forgetfulness. Aging increases the risk of Alzheimer's and other dementias. A family history of the illness increases your risk, according to the Mayo Clinic (USA).
Given that our genes are difficult to change (I won't get into epigenetics), what are some avoidable dementia risk factors? Certain drugs may cause cognitive deterioration.
Today we look at four drugs that may cause cognitive decline.
Dementia and benzodiazepines
Benzodiazepine sedatives increase brain GABA levels. Example benzodiazepines:
Diazepam (Valium) (Valium)
Alprazolam (Xanax) (Xanax)
Clonazepam (Klonopin) (Klonopin)
Addiction and overdose are benzodiazepine risks. Yes! These medications don't raise dementia risk.
USC study: Benzodiazepines don't increase dementia risk in older adults.
Benzodiazepines can produce short- and long-term amnesia. This memory loss hinders memory formation. Extreme cases can permanently impair learning and memory. Anterograde amnesia is uncommon.
2. Statins and dementia
Statins reduce cholesterol. They prevent a cholesterol-making chemical. Examples:
Atorvastatin (Lipitor) (Lipitor)
Fluvastatin (Lescol XL) (Lescol XL)
Lovastatin (Altoprev) (Altoprev)
Pitavastatin (Livalo, Zypitamag) (Livalo, Zypitamag)
Pravastatin (Pravachol) (Pravachol)
Rosuvastatin (Crestor, Ezallor) (Crestor, Ezallor)
Simvastatin (Zocor) (Zocor)
This finding is contentious. Harvard's Brigham and Womens Hospital's Dr. Joann Manson says:
“I think that the relationship between statins and cognitive function remains controversial. There’s still not a clear conclusion whether they help to prevent dementia or Alzheimer’s disease, have neutral effects, or increase risk.”
This one's off the dementia list.
3. Dementia and anticholinergic drugs
Anticholinergic drugs treat many conditions, including urine incontinence. Drugs inhibit acetylcholine (a brain chemical that helps send messages between cells). Acetylcholine blockers cause drowsiness, disorientation, and memory loss.
First-generation antihistamines, tricyclic antidepressants, and overactive bladder antimuscarinics are common anticholinergics among the elderly.
Anticholinergic drugs may cause dementia. One study found that taking anticholinergics for three years or more increased the risk of dementia by 1.54 times compared to three months or less. After stopping the medicine, the danger may continue.
4. Drugs for Parkinson's disease and dementia
Cleveland Clinic (USA) on Parkinson's:
Parkinson's disease causes age-related brain degeneration. It causes delayed movements, tremors, and balance issues. Some are inherited, but most are unknown. There are various treatment options, but no cure.
Parkinson's medications can cause memory loss, confusion, delusions, and obsessive behaviors. The drug's effects on dopamine cause these issues.
A 2019 JAMA Internal Medicine study found powerful anticholinergic medications enhance dementia risk.
Those who took anticholinergics had a 1.5 times higher chance of dementia. Individuals taking antidepressants, antipsychotic drugs, anti-Parkinson’s drugs, overactive bladder drugs, and anti-epileptic drugs had the greatest risk of dementia.
Anticholinergic medicines can lessen Parkinson's-related tremors, but they slow cognitive ability. Anticholinergics can cause disorientation and hallucinations in those over 70.
5. Antiepileptic drugs and dementia
The risk of dementia from anti-seizure drugs varies with drugs. Levetiracetam (Keppra) improves Alzheimer's cognition.
One study linked different anti-seizure medications to dementia. Anti-epileptic medicines increased the risk of Alzheimer's disease by 1.15 times in the Finnish sample and 1.3 times in the German population. Depakote, Topamax are drugs.

Bob Service
3 years ago
Did volcanic 'glasses' play a role in igniting early life?
Quenched lava may have aided in the formation of long RNA strands required by primitive life.
It took a long time for life to emerge. Microbes were present 3.7 billion years ago, just a few hundred million years after the 4.5-billion-year-old Earth had cooled enough to sustain biochemistry, according to fossils, and many scientists believe RNA was the genetic material for these first species. RNA, while not as complicated as DNA, would be difficult to forge into the lengthy strands required to transmit genetic information, raising the question of how it may have originated spontaneously.
Researchers may now have a solution. They demonstrate how basaltic glasses assist individual RNA letters, also known as nucleoside triphosphates, join into strands up to 200 letters long in lab studies. The glasses are formed when lava is quenched in air or water, or when melted rock generated by asteroid strikes cools rapidly, and they would have been plentiful in the early Earth's fire and brimstone.
The outcome has caused a schism among top origin-of-life scholars. "This appears to be a great story that finally explains how nucleoside triphosphates react with each other to create RNA strands," says Thomas Carell, a scientist at Munich's Ludwig Maximilians University. However, Harvard University's Jack Szostak, an RNA expert, says he won't believe the results until the study team thoroughly describes the RNA strands.
Researchers interested in the origins of life like the idea of a primordial "RNA universe" since the molecule can perform two different functions that are essential for life. It's made up of four chemical letters, just like DNA, and can carry genetic information. RNA, like proteins, can catalyze chemical reactions that are necessary for life.
However, RNA can cause headaches. No one has yet discovered a set of plausible primordial conditions that would cause hundreds of RNA letters—each of which is a complicated molecule—to join together into strands long enough to support the intricate chemistry required to kick-start evolution.
Basaltic glasses may have played a role, according to Stephen Mojzsis, a geologist at the University of Colorado, Boulder. They're high in metals like magnesium and iron, which help to trigger a variety of chemical reactions. "Basaltic glass was omnipresent on Earth at the time," he adds.
He provided the Foundation for Applied Molecular Evolution samples of five different basalt glasses. Each sample was ground into a fine powder, sanitized, and combined with a solution of nucleoside triphosphates by molecular biologist Elisa Biondi and her colleagues. The RNA letters were unable to link up without the presence of glass powder. However, when the molecules were mixed with the glass particles, they formed long strands of hundreds of letters, according to the researchers, who published their findings in Astrobiology this week. There was no need for heat or light. Biondi explains, "All we had to do was wait." After only a day, little RNA strands produced, yet the strands continued to grow for months. Jan Paek, a molecular biologist at Firebird Biomolecular Sciences, says, "The beauty of this approach is its simplicity." "Mix the components together, wait a few days, and look for RNA."
Nonetheless, the findings pose a slew of problems. One of the questions is how nucleoside triphosphates came to be in the first place. Recent study by Biondi's colleague Steven Benner suggests that the same basaltic glasses may have aided in the creation and stabilization of individual RNA letters.
The form of the lengthy RNA strands, according to Szostak, is a significant challenge. Enzymes in modern cells ensure that most RNAs form long linear chains. RNA letters, on the other hand, can bind in complicated branching sequences. Szostak wants the researchers to reveal what kind of RNA was produced by the basaltic glasses. "It irritates me that the authors made an intriguing initial finding but then chose to follow the hype rather than the research," Szostak says.
Biondi acknowledges that her team's experiment almost probably results in some RNA branching. She does acknowledge, however, that some branched RNAs are seen in species today, and that analogous structures may have existed before the origin of life. Other studies carried out by the study also confirmed the presence of lengthy strands with connections, indicating that they are most likely linear. "It's a healthy argument," says Dieter Braun, a Ludwig Maximilian University origin-of-life chemist. "It will set off the next series of tests."
Jamie Ducharme
3 years ago
How monkeypox spreads (and doesn't spread)
Monkeypox was rare until recently. In 2005, a research called a cluster of six monkeypox cases in the Republic of Congo "the longest reported chain to date."
That's changed. This year, over 25,000 monkeypox cases have been reported in 83 countries, indicating widespread human-to-human transmission.
What spreads monkeypox? Monkeypox transmission research is ongoing; findings may change. But science says...
Most cases were formerly animal-related.
According to the WHO, monkeypox was first diagnosed in an infant in the DRC in 1970. After that, instances were infrequent and often tied to animals. In 2003, 47 Americans contracted rabies from pet prairie dogs.
In 2017, Nigeria saw a significant outbreak. NPR reported that doctors diagnosed young guys without animal exposure who had genital sores. Nigerian researchers highlighted the idea of sexual transmission in a 2019 study, but the theory didn't catch on. “People tend to cling on to tradition, and the idea is that monkeypox is transmitted from animals to humans,” explains research co-author Dr. Dimie Ogoina.
Most monkeypox cases are sex-related.
Human-to-human transmission of monkeypox occurs, and sexual activity plays a role.
Joseph Osmundson, a clinical assistant professor of biology at NYU, says most transmission occurs in queer and gay sexual networks through sexual or personal contact.
Monkeypox spreads by skin-to-skin contact, especially with its blister-like rash, explains Ogoina. Researchers are exploring whether people can be asymptomatically contagious, but they are infectious until their rash heals and fresh skin forms, according to the CDC.
A July research in the New England Journal of Medicine reported that of more than 500 monkeypox cases in 16 countries as of June, 95% were linked to sexual activity and 98% were among males who have sex with men. WHO Director-General Tedros Adhanom Ghebreyesus encouraged males to temporarily restrict their number of male partners in July.
Is monkeypox a sexually transmitted infection (STI)?
Skin-to-skin contact can spread monkeypox, not simply sexual activities. Dr. Roy Gulick, infectious disease chief at Weill Cornell Medicine and NewYork-Presbyterian, said monkeypox is not a "typical" STI. Monkeypox isn't a STI, claims the CDC.
Most cases in the current outbreak are tied to male sexual behavior, but Osmundson thinks the virus might also spread on sports teams, in spas, or in college dorms.
Can you get monkeypox from surfaces?
Monkeypox can be spread by touching infected clothing or bedding. According to a study, a U.K. health care worker caught monkeypox in 2018 after handling ill patient's bedding.
Angela Rasmussen, a virologist at the University of Saskatchewan in Canada, believes "incidental" contact seldom distributes the virus. “You need enough virus exposure to get infected,” she says. It's conceivable after sharing a bed or towel with an infectious person, but less likely after touching a doorknob, she says.
Dr. Müge evik, a clinical lecturer in infectious diseases at the University of St. Andrews in Scotland, says there is a "spectrum" of risk connected with monkeypox. "Every exposure isn't equal," she explains. "People must know where to be cautious. Reducing [sexual] partners may be more useful than cleaning coffee shop seats.
Is monkeypox airborne?
Exposure to an infectious person's respiratory fluids can cause monkeypox, but the WHO says it needs close, continuous face-to-face contact. CDC researchers are still examining how often this happens.
Under precise laboratory conditions, scientists have shown that monkeypox can spread via aerosols, or tiny airborne particles. But there's no clear evidence that this is happening in the real world, Rasmussen adds. “This is expanding predominantly in communities of males who have sex with men, which suggests skin-to-skin contact,” she explains. If airborne transmission were frequent, she argues, we'd find more occurrences in other demographics.
In the shadow of COVID-19, people are worried about aerosolized monkeypox. Rasmussen believes the epidemiology is different. Different viruses.
Can kids get monkeypox?
More than 80 youngsters have contracted the virus thus far, mainly through household transmission. CDC says pregnant women can spread the illness to their fetus.
Among the 1970s, monkeypox predominantly affected children, but by the 2010s, it was more common in adults, according to a February study. The study's authors say routine smallpox immunization (which protects against monkeypox) halted when smallpox was eradicated. Only toddlers were born after smallpox vaccination halted decades ago. More people are vulnerable now.
Schools and daycares could become monkeypox hotspots, according to pediatric instances. Ogoina adds this hasn't happened in Nigeria's outbreaks, which is encouraging. He says, "I'm not sure if we should worry." We must be careful and seek evidence.
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Victoria Kurichenko
3 years ago
Here's what happened after I launched my second product on Gumroad.
One-hour ebook sales, affiliate relationships, and more.
If you follow me, you may know I started a new ebook in August 2022.
Despite publishing on this platform, my website, and Quora, I'm not a writer.
My writing speed is slow, 2,000 words a day, and I struggle to communicate cohesively.
In April 2022, I wrote a successful guide on How to Write Google-Friendly Blog Posts.
I had no email list or social media presence. I've made $1,600+ selling ebooks.
Evidence:
My first digital offering isn't a book.
It's an actionable guide with my tried-and-true process for writing Google-friendly content.
I'm not bragging.
Established authors like Tim Denning make more from my ebook sales with one newsletter.
This experience taught me writing isn't a privilege.
Writing a book and making money online doesn't require expertise.
Many don't consult experts. They want someone approachable.
Two years passed before I realized my own limits.
I have a brain, two hands, and Internet to spread my message.
I wrote and published a second ebook after the first's success.
On Gumroad, I released my second digital product.
Here's my complete Gumroad evaluation.
Gumroad is a marketplace for content providers to develop and sell sales pages.
Gumroad handles payments and client requests. It's helpful when someone sends a bogus payment receipt requesting an ebook (actual story!).
You'll forget administrative concerns after your first ebook sale.
After my first ebook sale, I did this: I made additional cash!
After every sale, I tell myself, "I built a new semi-passive revenue source."
This thinking shift helps me become less busy while increasing my income and quality of life.
Besides helping others, folks sell evergreen digital things to earn passive money.
It's in my second ebook.
I explain how I built and sold 50+ copies of my SEO writing ebook without being an influencer.
I show how anyone can sell ebooks on Gumroad and automate their sales process.
This is my ebook.
After publicizing the ebook release, I sold three copies within an hour.
Wow, or meh?
I don’t know.
The answer is different for everyone.
These three sales came from a small email list of 40 motivated fans waiting for my ebook release.
I had bigger plans.
I'll market my ebook on Medium, my website, Quora, and email.
I'm testing affiliate partnerships this time.
One of my ebook buyers is now promoting it for 40% commission.
Become my affiliate if you think your readers would like my ebook.
My ebook is a few days old, but I'm interested to see where it goes.
My SEO writing book started without an email list, affiliates, or 4,000 website visitors. I've made four figures.
I'm slowly expanding my communication avenues to have more impact.
Even a small project can open doors you never knew existed.
So began my writing career.
In summary
If you dare, every concept can become a profitable trip.
Before, I couldn't conceive of creating an ebook.
How to Sell eBooks on Gumroad is my second digital product.
Marketing and writing taught me that anything can be sold online.

William Anderson
3 years ago
When My Remote Leadership Skills Took Off
4 Ways To Manage Remote Teams & Employees
The wheels hit the ground as I landed in Rochester.
Our six-person satellite office was now part of my team.
Their manager only reported to me the day before, but I had my ticket booked ahead of time.
I had managed remote employees before but this was different. Engineers dialed into headquarters for every meeting.
So when I learned about the org chart change, I knew a strong first impression would set the tone for everything else.
I was either their boss, or their boss's boss, and I needed them to know I was committed.
Managing a fleet of satellite freelancers or multiple offices requires treating others as more than just a face behind a screen.
You must comprehend each remote team member's perspective and daily interactions.
The good news is that you can start using these techniques right now to better understand and elevate virtual team members.
1. Make Visits To Other Offices
If budgeted, visit and work from offices where teams and employees report to you. Only by living alongside them can one truly comprehend their problems with communication and other aspects of modern life.
2. Have Others Come to You
• Having remote, distributed, or satellite employees and teams visit headquarters every quarter or semi-quarterly allows the main office culture to rub off on them.
When remote team members visit, more people get to meet them, which builds empathy.
If you can't afford to fly everyone, at least bring remote managers or leaders. Hopefully they can resurrect some culture.
3. Weekly Work From Home
No home office policy?
Make one.
WFH is a team-building, problem-solving, and office-viewing opportunity.
For dial-in meetings, I started working from home on occasion.
It also taught me which teams “forget” or “skip” calls.
As a remote team member, you experience all the issues first hand.
This isn't as accurate for understanding teams in other offices, but it can be done at any time.
4. Increase Contact Even If It’s Just To Chat
Don't underestimate office banter.
Sometimes it's about bonding and trust, other times it's about business.
If you get all this information in real-time, please forward it.
Even if nothing critical is happening, call remote team members to check in and chat.
I guarantee that building relationships and rapport will increase both their job satisfaction and yours.

Tim Denning
3 years ago
I gave up climbing the corporate ladder once I realized how deeply unhappy everyone at the top was.
Restructuring and layoffs cause career reevaluation. Your career can benefit.
Once you become institutionalized, the corporate ladder is all you know.
You're bubbled. Extremists term it the corporate Matrix. I'm not so severe because the business world brainwashed me, too.
This boosted my corporate career.
Until I hit bottom.
15 months later, I view my corporate life differently. You may wish to advance professionally. Read this before you do.
Your happiness in the workplace may be deceptive.
I've been fortunate to spend time with corporate aces.
Working for 2.5 years in banking social media gave me some of these experiences. Earlier in my career, I recorded interviews with business leaders.
These people have titles like Chief General Manager and Head Of. New titles brought life-changing salaries.
They seemed happy.
I’d pass them in the hallway and they’d smile or shake my hand. I dreamt of having their life.
The ominous pattern
Unfiltered talks with some of them revealed a different world.
They acted well. They were skilled at smiling and saying the correct things. All had the same dark pattern, though.
Something felt off.
I found my conversations with them were generally for their benefit. They hoped my online antics as a writer/coach would shed light on their dilemma.
They'd tell me they wanted more. When you're one position away from CEO, it's hard not to wonder if this next move will matter.
What really displeased corporate ladder chasers
Before ascending further, consider these.
Zero autonomy
As you rise in a company, your days get busier.
Many people and initiatives need supervision. Everyone expects you to know business details. Weak when you don't. A poor leader is fired during the next restructuring and left to pursue their corporate ambition.
Full calendars leave no time for reflection. You can't have a coffee with a friend or waste a day.
You’re always on call. It’s a roll call kinda life.
Unable to express oneself freely
My 8 years of LinkedIn writing helped me meet these leaders.
I didn't think they'd care. Mistake.
Corporate leaders envied me because they wanted to talk freely again without corporate comms or a PR firm directing them what to say.
They couldn't share their flaws or inspiring experiences.
They wanted to.
Every day they were muzzled eroded by their business dream.
Limited family time
Top leaders had families.
They've climbed the corporate ladder. Nothing excellent happens overnight.
Corporate dreamers rarely saw their families.
Late meetings, customer functions, expos, training, leadership days, team days, town halls, and product demos regularly occurred after work.
Or they had to travel interstate or internationally for work events. They used bags and motel showers.
Initially, they said business class flights and hotels were nice. They'd get bored. 5-star hotels become monotonous.
No hotel beats home.
One leader said he hadn't seen his daughter much. They used to Facetime, but now that he's been gone so long, she rarely wants to talk to him.
So they iPad-parented.
You're miserable without your family.
Held captive by other job titles
Going up the business ladder seems like a battle.
Leaders compete for business gains and corporate advancement.
I saw shocking filthy tricks. Leaders would lie to seem nice.
Captives included top officials.
A different section every week. If they ran technology, the Head of Sales would argue their CRM cost millions. Or an Operations chief would battle a product team over support requests.
After one conflict, another began.
Corporate echelons are antagonistic. Huge pay and bonuses guarantee bad behavior.
Overly centered on revenue
As you rise, revenue becomes more prevalent. Most days, you'd believe revenue was everything. Here’s the problem…
Numbers drain us.
Unless you're a closet math nerd, contemplating and talking about numbers drains your creativity.
Revenue will never substitute impact.
Incapable of taking risks
Corporate success requires taking fewer risks.
Risks can cause dismissal. Risks can interrupt business. Keep things moving so you may keep getting paid your enormous salary and bonus.
Restructuring or layoffs are inevitable. All corporate climbers experience it.
On this fateful day, a small few realize the game they’ve been trapped in and escape. Most return to play for a new company, but it takes time.
Addiction keeps them trapped. You know nothing else. The rest is strange.
You start to think “I’m getting old” or “it’s nearly retirement.” So you settle yet again for the trappings of the corporate ladder game to nowhere.
Should you climb the corporate ladder?
Let me end on a surprising note.
Young people should ascend the corporate ladder. It teaches you business skills and helps support your side gig and (potential) online business.
Don't get trapped, shackled, or muzzled.
Your ideas and creativity become stifled after too much gaming play.
Corporate success won't bring happiness.
Find fulfilling employment that matters. That's it.
