News
Sunflowers make small moves to maximize their Sun exposure – physicists can model them to predict how they grow
Charles Darwin’s detailed observations of plant movements, such as sunflower circumnutation and self-organization, reveal how randomness helps plants optimize growth and adapt to their environments. Sunflowers!
Last Updated on March 6, 2026 by Daily News Staff
Chantal Nguyen, University of Colorado Boulder
Sunflowers make small moves to maximize their Sun exposure – physicists can model them to predict how they grow
Most of us aren’t spending our days watching our houseplants grow. We see their signs of life only occasionally – a new leaf unfurled, a stem leaning toward the window.
But in the summer of 1863, Charles Darwin lay ill in bed, with nothing to do but watch his plants so closely that he could detect their small movements to and fro. The tendrils from his cucumber plants swept in circles until they encountered a stick, which they proceeded to twine around.
“I am getting very much amused by my tendrils,” he wrote.
This amusement blossomed into a decadeslong fascination with the little-noticed world of plant movements. He compiled his detailed observations and experiments in a 1880 book called “The Power of Movement in Plants.”
In one study, he traced the motion of a carnation leaf every few hours over the course of three days, revealing an irregular looping, jagged path. The swoops of cucumber tendrils and the zags of carnation leaves are examples of inherent, ubiquitous plant movements called circumnutations – from the Latin circum, meaning circle, and nutare, meaning to nod.
Circumnutations vary in size, regularity and timescale across plant species. But their exact function remains unclear.
I’m a physicist interested in understanding collective behavior in living systems. Like Darwin, I’m captivated by circumnutations, since they may underlie more complex phenomena in groups of plants.
Sunflower patterns
A 2017 study revealed a fascinating observation that got my colleagues and me wondering about the role circumnutations could play in plant growth patterns. In this study, researchers found that sunflowers grown in a dense row naturally formed a near-perfect zigzag pattern, with each plant leaning away from the row in alternating directions.
This pattern allowed the plants to avoid shade from their neighbors and maximize their exposure to sunlight. These sunflowers flourished.
Researchers then planted some plants at the same density but constrained them so that they could grow only upright without leaning. These constrained plants produced less oil than the plants that could lean and get the maximum amount of sun.
While farmers can’t grow their sunflowers quite this close together due to the potential for disease spread, in the future they may be able to use these patterns to come up with new planting strategies.
Self-organization and randomness
This spontaneous pattern formation is a neat example of self-organization in nature. Self-organization refers to when initially disordered systems, such as a jungle of plants or a swarm of bees, achieve order without anything controlling them. Order emerges from the interactions between individual members of the system and their interactions with the environment.
Somewhat counterintuitively, noise – also called randomness – facilitates self-organization. Consider a colony of ants.
Ants secrete pheromones behind them as they crawl toward a food source. Other ants find this food source by following the pheromone trails, and they further reinforce the trail they took by secreting their own pheromones in turn. Over time, the ants converge on the best path to the food, and a single trail prevails.
But if a shorter path were to become possible, the ants would not necessarily find this path just by following the existing trail.
If a few ants were to randomly deviate from the trail, though, they might stumble onto the shorter path and create a new trail. So this randomness injects a spontaneous change into the ants’ system that allows them to explore alternative scenarios.
Eventually, more ants would follow the new trail, and soon the shorter path would prevail. This randomness helps the ants adapt to changes in the environment, as a few ants spontaneously seek out more direct ways to their food source.
In biology, self-organized systems can be found at a range of scales, from the patterns of proteins inside cells to the socially complex colonies of honeybees that collectively build nests and forage for nectar.
Randomness in sunflower self-organization
So, could random, irregular circumnutations underpin the sunflowers’ self-organization?
My colleagues and I set out to explore this question by following the growth of young sunflowers we planted in the lab. Using cameras that imaged the plants every five minutes, we tracked the movement of the plants to see their circumnutatory paths.
We saw some loops and spirals, and lots of jagged movements. These ultimately appeared largely random, much like Darwin’s carnation. But when we placed the plants together in rows, they began to move away from one another, forming the same zigzag configurations that we’d seen in the previous study.
We analyzed the plants’ circumnutations and found that at any given time, the direction of the plant’s motion appeared completely independent of how it was moving about half an hour earlier. If you measured a plant’s motion once every 30 minutes, it would appear to be moving in a completely random way.
We also measured how much the plant’s leaves grew over the course of two weeks. By putting all of these results together, we sketched a picture of how a plant moved and grew on its own. This information allowed us to computationally model a sunflower and simulate how it behaves over the course of its growth.
A sunflower model
We modeled each plant simply as a circular crown on a stem, with the crown expanding according to the growth rate we measured experimentally. The simulated plant moved in a completely random way, taking a “step” every half hour.
We created the model sunflowers with circumnutations of lower or higher intensity by tweaking the step sizes. At one end of the spectrum, sunflowers were much more likely to take tiny steps than big ones, leading to slow, minimal movement on average. At the other end were sunflowers that are equally as likely to take large steps as small steps, resulting in highly irregular movement. The real sunflowers we observed in our experiment were somewhere in the middle.
Plants require light to grow and have evolved the ability to detect shade and alter the direction of their growth in response.
We wanted our model sunflowers to do the same thing. So, we made it so that two plants that get too close to each other’s shade begin to lean away in opposite directions.
Finally, we wanted to see whether we could replicate the zigzag pattern we’d observed with the real sunflowers in our model.
First, we set the model sunflowers to make small circumnutations. Their shade avoidance responses pushed them away from each other, but that wasn’t enough to produce the zigzag – the model plants stayed stuck in a line. In physics, we would call this a “frustrated” system.
Then, we set the plants to make large circumnutations. The plants started moving in random patterns that often brought the plants closer together rather than farther apart. Again, no zigzag pattern like we’d seen in the field.
But when we set the model plants to make moderately large movements, similar to our experimental measurements, the plants could self-organize into a zigzag pattern that gave each sunflower optimal exposure to light.
So, we showed that these random, irregular movements helped the plants explore their surroundings to find desirable arrangements that benefited their growth.
Plants are much more dynamic than people give them credit for. By taking the time to follow them, scientists and farmers can unlock their secrets and use plants’ movement to their advantage.
Chantal Nguyen, Postdoctoral Associate at the BioFrontiers Institute, University of Colorado Boulder
This article is republished from The Conversation under a Creative Commons license. Read the original article.
STM Daily News is a vibrant news blog dedicated to sharing the brighter side of human experiences. Emphasizing positive, uplifting stories, the site focuses on delivering inspiring, informative, and well-researched content. With a commitment to accurate, fair, and responsible journalism, STM Daily News aims to foster a community of readers passionate about positive change and engaged in meaningful conversations. Join the movement and explore stories that celebrate the positive impacts shaping our world.
https://stmdailynews.com/category/stories-this-moment
health and wellness
Zepbound Linked to Lower Healthcare Costs in Adults 55+ With Obesity, Real-World Study Suggests
A new real-world study of adults over age 55 with overweight or obesity found that sustained use of Zepbound (tirzepatide) for weight management was associated with lower healthcare costs over time compared with similar adults who were not treated. Eli Lilly and Company said the findings were driven in part by lower rates of hospital admissions and emergency department visits, and were published in Diabetes, Obesity and Metabolism.
What the study found
According to Lilly, researchers estimated healthcare cost differences over time (excluding the cost of Zepbound itself) using two established analytic methods. Across both approaches, monthly healthcare costs were lower, on average, among older adults who stayed on Zepbound.
Key estimates reported in the release include:
- At six months: costs were up to 15% lower (up to $181 per patient, per month).
- At 12 months: the estimated difference widened to as much as $607 per patient, per month, reflecting up to 38% lower costs than those not treated (estimates varied by model).
In the primary analysis, adults over 55 treated with Zepbound had lower rates of hospital admissions and emergency department visits across every follow-up period, along with numerically higher rates of routine outpatient and office visitsa pattern the company said was consistent with greater engagement in routine care.
Why Medicare is part of the conversation
Lilly said the cost findings may be relevant for older adults, including those in Medicares GLP-1 Bridge program. The company noted that beginning at six months, estimated healthcare savings nearly covered the programs monthly treatment cost of $195 per patient, per month, and by 12 months the estimated savings exceeded the reported monthly treatment cost.
Its important to note the release also emphasizes a limitation: claims data do not capture Zepbounds net price, and the study excluded the cost of Zepbound from total treatment costs. That means the reported differences reflect potential savings elsewhere in care that could offset treatment costs, not the full net cost impact.
Who was included in the analysis
The retrospective observational cohort study used Komodos Healthcare Map, a database of de-identified claims data from more than 330 million individuals enrolled in U.S. healthcare plans. The analysis included 15,843 adults over age 55 (mean age 64.5) with obesity or overweight plus at least one obesity-related complication who initiated Zepbound between November 2023 and September 2025. Each Zepbound user was matched 1:1 with a control participant who met the same eligibility criteria but did not initiate GLP-1 or GIP/GLP-1 receptor agonist medication.
What Zepbound is
Zepbound (tirzepatide) is a dual GIP and GLP-1 receptor agonist indicated for adults with obesity, or some adults with overweight who also have at least one weight-related medical problem, to lose weight and keep it off. Lilly also noted Zepbound is FDA-approved to treat adults with moderate-to-severe obstructive sleep apnea and obesity, and should be used alongside a reduced-calorie diet and increased physical activity.
Safety summary (high level)
The release includes an indications and safety summary with warnings. Among other risks, Lilly notes Zepbound carries a warning about thyroid tumors, including thyroid cancer, and may cause serious side effects such as severe stomach problems, dehydration leading to kidney problems, gallbladder problems, pancreatitis, serious allergic reactions, and low blood sugar (especially when used with certain diabetes medicines). Patients should talk with a healthcare provider about risks and whether the medication is appropriate for them.
Related Links
- Zepbound (official product site): https://zepbound.lilly.com/
- Lilly newsroom: https://www.lilly.com/news
- Journal page (publisher hub): https://dom-pubs.onlinelibrary.wiley.com/journal/14631326
- Medicare (official): https://www.medicare.gov/
- FDA MedWatch (side effect reporting): https://www.fda.gov/medwatch
Source
- PRNewswire / Eli Lilly and Company press release (Aug. 26, 2026): Zepbound linked to lower healthcare costs in adults over age 55 with obesity according to a real-world study
💪 Your health journey starts here! Explore the latest health news, fitness tips, wellness trends, and healthy living advice. Share your thoughts in the comments and subscribe to the STM Daily News newsletter to stay informed and inspired every day.
Economy
U.S. Consumer Confidence Slips as Americans Grow More Cautious About the Future
U.S. consumer confidence edged lower in August as Americans became more pessimistic about jobs, income and business conditions over the next six months, despite improved views of the current economy.
NEW YORK — U.S. consumer confidence edged lower in August as Americans expressed greater concern about future business conditions, jobs and household income, even as their assessment of the current economy improved.
The Conference Board reported that its Consumer Confidence Index fell 0.8 points to 89.4 in August, down from 90.2 in July.
The relatively small decline, however, masks a widening gap between how consumers view conditions today and what they expect in the months ahead.
The Present Situation Index, which measures consumers’ assessment of current business and labor market conditions, climbed 6.8 points to 121.2, reversing three consecutive months of declines.
Meanwhile, the Expectations Index, which measures the short-term outlook for income, business and employment conditions, dropped 5.8 points to 68.2.
“Consumer confidence moderated slightly in August for a second consecutive month,” Dana M. Peterson, chief economist at The Conference Board, said in the organization’s Aug. 25 release.
Jobs Look Better Today — But Consumers Worry About Tomorrow
Americans’ perceptions of the current labor market improved considerably during August. About 27% said jobs were plentiful, up from 24.4% in July, while 19.5% said jobs were hard to get, down from 21.7%.
The outlook for the next six months was considerably weaker.
Only 14.6% expected more jobs to become available, compared with 16.4% in July. At the same time, 26.1% expected fewer jobs.
Consumers were also less optimistic about their incomes. About 17.6% expected their income to increase, down from 19.5% in July, while 13.8% expected their income to decline.
Prices Remain on Consumers’ Minds
Inflation continues to influence how Americans feel about the economy. According to The Conference Board, consumers’ written responses frequently mentioned prices, oil and gasoline, food and groceries, trade, jobs, and war or conflict.
Average and median expectations for inflation over the next 12 months also increased slightly.
Interest rates remain another concern. More than six in 10 consumers — 61.3% — expected interest rates to rise over the next year, although that was slightly lower than the 62% recorded in July.
Consumers Are Still Planning to Spend
The softer outlook hasn’t eliminated Americans’ willingness to make purchases.
Auto-buying expectations remained strong on a six-month moving-average basis, while homebuying expectations declined slightly in August but remained on a longer-term upward trend after hitting decade lows in early 2024.
Restaurants, bars and takeout; utilities; and streaming, internet and mobile services ranked among consumers’ leading planned service expenses.
Consumers were less enthusiastic about discretionary activities including movies, personal-travel hotels, airfare, amusement parks, museums and historical sites.
Why It Matters
The August numbers paint a mixed picture of the American consumer.
People are seeing some improvement in the economy they are experiencing today, particularly in the labor market. But their expectations for the next six months are becoming noticeably more cautious.
That divide matters because consumer spending represents a major part of U.S. economic activity. If concerns about employment, inflation and household income begin translating into reduced spending, weakening confidence could eventually become more significant for the broader economy.
For now, the August survey suggests Americans haven’t stopped spending — but they’re increasingly keeping an eye on what may be coming next.
The preliminary August Consumer Confidence Survey was conducted online for The Conference Board by Toluna. The survey period was Aug. 3–16, 2026.
Source: The Conference Board, August 2026 Consumer Confidence Survey®, released Aug. 25, 2026.
STM Daily News Economy News Brief
Sources
- The Conference Board — U.S. Consumer Confidence, August 2026 — Primary source for the August Consumer Confidence Index, Present Situation Index and Expectations Index.
- The Conference Board — Consumer Confidence Survey & Data — Consumer confidence survey information, methodology and release schedule.
Related Economic Data
- Bureau of Economic Analysis — Consumer Spending — Official U.S. data tracking personal consumption expenditures. Consumer spending increased 0.2% in July 2026.
- BEA — Personal Income and Outlays, July 2026 — Tracks household income, disposable income, consumer spending and saving.
- Bureau of Labor Statistics — Consumer Price Index — Official inflation data. The July 2026 CPI was up 3.4% from a year earlier; August CPI is scheduled for release September 11.
- Federal Reserve — Consumer Credit — Federal Reserve data covering revolving and nonrevolving consumer credit.
Lifestyle
California and Minnesota Face $1B Medicaid Funding Hold
The Trump administration is withholding more than $1 billion in Medicaid funding from California and Minnesota over disputed medical claims. A social-policy historian examines how concerns about fraud have historically been used to justify funding cuts and undermine public confidence in Medicaid.
Ben Zdencanovic, University of Cambridge
California and Minnesota Face $1B Medicaid Funding Hold
The Trump administration announced on July 21, 2026, that it’s withholding US$867 million in federal healthcare funding for California and $200 million for Minnesota – a total of more than $1 billion.
Federal officials said the two states had failed to provide sufficient evidence that a number of disputed medical claims were legitimate. These include bills for in-home care and other services covered by the two states’ Medicaid programs for low-income residents.
Medicaid administrators say the funds can be recovered if the states supply the requested documentation. But the action is highly unusual: Typically, Medicaid officials partner with states to conduct an audit when they suspect fraud, a careful process that often takes years.
It’s the second time in 2026 that the Trump administration has withheld or deferred federal Medicaid funds for several states, including California and Minnesota, because of alleged fraud and abuse. The Democratic governors of those states have called the decision a politically motivated attack on their constituents.
I’m a historian of social policy who led the first comprehensive historical overview of Medi-Cal, California’s statewide Medicaid system. I’ve found that U.S. leaders have long used the language of fraud and abuse to blur the line between correcting very real failures within Medicaid and – as I believe the Trump administration is currently doing – discrediting and defunding the program itself.
Slashing the safety net
The Medicaid restrictions are part of the Trump administration’s overall efforts to slash federal funding for the safety net.
The large tax-and-spending bill that Trump signed into law in July 2025 as the cornerstone of his second-term agenda pared eligibility for Medicaid by introducing work requirements for some adults. It is cutting close to $1 trillion in federal spending on the program over the next decade.
Researchers estimate that almost 12 million people, on top of the estimated 28 million without health insurance in 2025, could become uninsured by 2034 due to these changes. By mid-2026, more than 3 million people had already lost their insurance coverage due to Republican changes to the Affordable Care Act.
‘Padlocking’ the ‘cookie jar’
In February 2026, Vice President JD Vance, Health Secretary Robert F. Kennedy Jr. and Dr. Mehmet Oz, the administrator of the Centers for Medicare & Medicaid Services, or CMS, announced a new anti-fraud initiative called Comprehensive Regulations to Uncover Suspicious Healthcare.
Also known by its rather unsubtle acronym, CRUSH, this initiative is taking unprecedented steps to withhold and defer funds in response to suspected fraud. “CMS is done trying to catch fraudsters with their hands in the cookie jar,” Oz said in announcing CRUSH’s formation. “Instead, we’re padlocking the jar and letting them starve.”
To be sure, Medicaid fraud, waste and abuse – such as providers billing Medicaid for services that are unnecessary or never rendered – are very real problems that cost taxpayers billions of dollars annually. They do divert funds from the low-income and disabled Americans enrolled in the program.
But the Trump administration’s latest moves are part of a much broader history of weaponizing Medicaid fraud and abuse – both real and imagined. I see them as a politicized attempt to prove that Medicaid itself is wasteful, that state governments cannot be trusted to administer federal money, and that public benefits inevitably invite dishonesty.
Providing little oversight at the start
Medicaid was established, along with Medicare for older adults, in 1965 as part of President Lyndon B. Johnson’s “Great Society” reforms. Despite providing millions of Americans with health insurance coverage for the first time, these programs had few centralized mechanisms for the kind of federal oversight that could prevent and catch fraud and abuse.
And the sheer scale and complexity of the Medicaid system – joint federal-state funding, varying eligibility requirements, millions of enrollees and thousands of providers – created opportunities for questionable billing practices among providers.
The 1970s saw a number of highly publicized Medicaid scandals involving nursing homes, laboratories, pharmacies and so-called “Medicaid mills” – healthcare providers that sought to bill the government for large numbers of Medicaid patients for shoddy and often fraudulent care.
A series of high-profile congressional investigations spurred demand for stronger Medicaid oversight and enforcement. That led to the Medicare-Medicaid Anti-Fraud and Abuse Amendments of 1977, which established the national Medicaid Fraud Control Units program.
The state-run Medicaid Fraud Control Units received generous federal matching funds to investigate and prosecute fraud.
The most serious Medicaid fraud was generally committed by healthcare providers and contractors, not patients. Medicaid Fraud Control Units were principally responsible for investigating providers, while also prosecuting the abuse and neglect of patients whose care was billed to Medicaid.
At the same time, however, Medicaid was becoming entangled in a broader political debate over social spending, whether many Americans were becoming too dependent on government benefits, and the alleged use of benefits by people who should not have received them. In the 1980s and 1990s, widely circulated stories about Medicaid exposed fraud and malfeasance by providers.
But disproportionately, they also highlighted the comparatively few instances of fraud by people enrolled in the program, such as cases where they submitted false receipts for covered medically related travel or sold drugs they obtained through Medicaid for free or at low cost.
Using Medicare fraud to justify spending cuts
The distinction between Medicaid and cash assistance programs, such as the Aid to Families with Dependent Children “welfare” program, frequently disappeared in political rhetoric. False or exaggerated stories that portrayed African American single mothers living extravagantly while fraudulently claiming welfare benefits became potent symbols of supposed government failure.
While campaigning as a presidential candidate, Ronald Reagan seized on this trope of the “welfare queen” in his attacks on social spending.
By the mid-1990s, opposition to welfare programs had become increasingly bipartisan. Politicians in both parties often used tales of Medicaid fraud on the part of providers and recipients to justify tighter eligibility rules and spending cuts.
Federal oversight expanded further with the Deficit Reduction Act of 2005, which created the Medicaid Integrity Program and strengthened federal oversight of state programs. The Affordable Care Act, the landmark healthcare legislation Congress passed in 2010, added new measures to screen providers and verify billing.
Concerns about Medicaid’s “integrity” became highly politicized in the debates surrounding the ACA. Critics of Medicaid expansion argued that increasing the number of people who could get health insurance through the program would increase fraud and improper enrollment. Supporters of expanding Medicaid to help more Americans gain health insurance maintained that anti-fraud rhetoric often disguised ideological opposition to the program’s expansion.
Blurring distinctions then and now
For the six decades that this program has helped millions of low-income Americans get healthcare, politicians have blurred the distinction between protecting Medicaid from abuse and using abuse to discredit Medicaid itself.
In my view, the Trump administration’s campaigns against California and Minnesota continue that pattern. It is using real weaknesses within Medicaid to advance much broader political arguments: that Democratic states cannot be trusted, that public benefits naturally invite abuse, and that withholding funds is itself a form of reform.
The result will no doubt be that fewer low-income Americans will be able to get the healthcare they need.
Ben Zdencanovic, Assistant Professor of U.S. History, University of Cambridge
This article is republished from The Conversation under a Creative Commons license. Read the original article.
💪 Your health journey starts here! Explore the latest health news, fitness tips, wellness trends, and healthy living advice. Share your thoughts in the comments and subscribe to the STM Daily News newsletter to stay informed and inspired every day.
