Hundreds of millions of tons of single-use plastic ends up in landfills every year, and even the small percentage of plastic that gets recycled can’t last forever. But our group of materials scientists has developed a new method for creating and deconstructing polymers that could lead to more easily recycled plastics – ones that don’t require you to carefully sort out all your recycling on trash day.
In the century since their conception, people have come to understand the enormous impacts – beneficial as well as detrimental – plastics have on human lives and the environment. As a group of polymer scientists dedicated to inventing sustainable solutions for real-world problems, we set out to tackle this issue by rethinking the way polymers are designed and making plastics with recyclability built right in.
Why use plastics, anyway?
Everyday items including milk jugs, grocery bags, takeout containers and even ropes are made from a class of polymers called polyolefins. Polyolefins make up around half of the plastics produced and disposed of every year.
These polymers are used in plastics commonly labeled as HDPE, LLDPE or PP, or by their recycling codes #2, #4 and #5, respectively. These plastics are incredibly durable because the chemical bonds that make them up are extremely stable. But in a world set up for single-use consumption, this is no longer a design feature but rather a design flaw.
Imagine if half of the plastics used today were recyclable by twice as many processes as they are now. While that wouldn’t get the recycling rate to 100%, a jump from single digits – currently around 9% – to double digits would make a big dent in the plastics produced, the plastics accumulated in the environment and their capacity for recycling and reuse.
Recycling methods we already have
Even the plastics that make it to a recycling facility can’t be reused in exactly the same way they were used before – the recycling process degrades the material, so it loses utility and value. Instead of making a plastic cup that is downgraded each time it gets recycled, manufacturers could potentially make plastics once, collect them and reuse them on and on.
Conventional recycling requires careful sorting of all the collected materials, which can be hard with so many different plastics. Here in the U.S., collection happens mainly through single stream recycling – everything from metal cans, glass bottles, cardboard boxes and plastic cups end up in the same bin. Separating paper from metal doesn’t require complex technology, but sorting a polypropylene container from a polyethylene milk jug is hard to do without the occasional mistake.
When two different plastics are mixed together during recycling, their useful properties are hugely reduced – to the point of making them useless.
But say you can recycle one of these plastics by a different method, so it doesn’t end up contaminating the recycling stream. When we mixed samples of polypropylene with a polymer we made, we were still able to depolymerize – or break down the material – and regain our building blocks without chemically affecting the polypropylene. This indicated that a contaminated waste stream could still recover its value, and the material in it could go on to be recycled, either mechanically or chemically.
Plastics we need − but more recyclable
In a study published in October 2023, our team developed a series of polymers with only two simple building blocks – one soft polymer and one hard polymer – that mimicked polyolefins but could also be chemically recycled.
Connecting two different polymers together multiple times until they form a single, long molecule creates what’s called a multiblock polymer. Just by adjusting how much of each polymer type goes into the multiblock polymer, our team created a wide range of materials with properties that spanned across polyolefin types. But creating these multiblock polymers is easier said than done.
To link these hard and soft polymers, we adapted a technique that had previously been used only on very small molecules. This method is improved relative to traditional methods of making polymers in a step-by-step fashion, developed in the 1920s, where the reactive groups on the end of the molecules need to be exactly matched.
In our method, the reactive groups are now the same as each other, meaning we didn’t have to worry about pairing the ends of each building block to make polymers that can compete with the polyolefins we already use. Using the same strategy, applied in reverse by adding hydrogen, we could disconnect the polymers back into their building blocks and easily separate them to use again.
With an almost twofold increase in annual plastic use projected through 2050, the complexity and quantity of plastic recycling will only increase. It’s an important consideration when designing new materials and products.
Using just two building blocks to make plastics that have a huge variety of properties can go a long way toward reducing and streamlining the number of different plastics used to make the products we need. Instead of needing one plastic to make something pliable, another for something stiff, and a third, fourth and fifth for properties in between, we could control the behavior of plastics by just changing how much of each building block is there.
Although we’re still in the process of answering some big questions about these polymers, we believe this work is a step in the right direction toward more sustainable plastics.
We were able to create materials that mimic the properties of plastics the world relies on, and our sights are now set on creating plastic compositions that you couldn’t with existing methods.
theconversation.com – Amy Cooter, Director of Research, Academic Development and Innovation at the Center on Terrorism, Extremism and Counterterrorism, Middlebury – 2025-01-22 15:12:00
Several of the highest-profile figures in the Jan. 6, 2021, insurrection were charged with, and convicted of, the crime of seditious conspiracy, which is defined as the act of getting together with other people to overthrow the government. They were among the roughly 1,500 people involved in the insurrection who were pardoned or had their prison sentences commuted by Donald Trump on his first day in office.
Seditious conspiracy is a serious crime of conspiring to overthrow the government or stop its normal functioning. Historically, seditious conspiracy has been difficult to successfully prosecute.
In 2009, for example, a state judge ruled that prosecutors had failed to provide sufficient evidence for members of the Michigan Hutaree militia to go to trial on that charge. Certain militia members had been accused of plotting violence against police officers. While some members faced other charges for their actions, the judge determined that a plot against law enforcement was not sufficient to support charges of attempting to overthrow the government.
In contrast, the U.S. Department of Justice charged 18 people associated with the Jan. 6 attack on the U.S. Capitol with that crime, asserting that they had intended to “oppose by force the lawful transfer of presidential power” or had committed other actions that would undermine the entire system of government.
Of those 18, four pleaded guilty, and 10 were found guilty at trial. The remaining four were found not guilty of seditious conspiracy but were convicted of other crimes that were related to the insurrection.
Capitol entry not required
Oath Keepers militia leader Stewart Rhodes’ seditious conspiracy conviction was especially significant because, unlike some other defendants, Rhodes did not physically enter the Capitol building. He was instead in “the restricted area of Capitol grounds,” according to a Justice Department statement.
His conviction was based in part on his communications, including text messages, both before Jan. 6 and on the day itself. Prosecutors successfully argued that these communications were part of a broader conspiracy to disrupt the election certification by organizing and encouraging others to participate in more direct action.
The full effect that the pardons will have on militia actors and related groups in coming years is uncertain: Will the pardons send the message to all Americans that political violence is acceptable, or at least that it can be overlooked or forgiven if the right political figures are in power?
Amy Cooter, Director of Research, Academic Development and Innovation at the Center on Terrorism, Extremism and Counterterrorism, Middlebury
Today, GLP-1 drugs, including Wegovy, Mounjaro and Zepbound, have become household names and key tools in the fight against obesity: 1 in 8 American adults say they have used a GLP-1 drug, and forecasts show that by 2030, 1 in 10 Americans will likely be using these medications.
Now, research from my lab and others suggests that GLP-1 drugs could help treat dozens of other ailments as well, including cognitive issues and addiction problems. However, my colleagues and I also found previously unidentified risks.
I am a physician-scientist and I direct a clinical epidemiology center focused on addressing public health’s most urgent questions. My team works to address critical knowledge gaps about COVID-19, long COVID, influenza, vaccines, effectiveness and risks of commonly used drugs, and more.
On Jan. 20, 2025, my team published a study of more than 2.4 million people that evaluated the risks and benefits of GLP-1 drugs across 175 possible health outcomes. We found that these drugs lowered risks of 42 health outcomes, nearly a quarter of the total that we analyzed. These include neurocognitive disorders such as Alzheimer’s disease and dementia, substance use and addiction disorders, clotting disorders and several other conditions.
Unfortunately, we also found that GLP-1 drugs come with significant side effects and increase the risk of 19 health conditions we studied, such as gastrointestinal issues, kidney stones and acute pancreatitis, in which the pancreas becomes inflamed and dysfunctional.
Cognitive benefits
One of the most important health benefits we found was that the GLP-1 drugs lowered the risk of neurodegenerative disorders, including Alzheimer’s disease and dementia. These findings align with other research, including evidence from preclinical studies showing that these drugs may reduce inflammation in the brain and enhance the brain’s ability to form and strengthen connections between its cells, improving how they communicate with one another. These effects contribute to mitigating cognitive decline.
All of these studies strongly point to a potential therapeutic use of GLP-1 drugs in treatment of the cognitive decline. Ongoing randomized trials – the gold standard for evaluating new uses of drugs – are looking at the effects of GLP-1 drugs in early Alzheimer’s disease, with results expected later in 2025.
Curbing addiction and suicidal ideation
GLP-1 drugs have also demonstrated potential in reducing risks of several substance use disorders such as those involving alcohol, tobacco, cannabis, opioids and stimulants. This may be due to the ability of these drugs to modulate reward pathways, impulse control and inflammatory processes in the brain.
The effectiveness of GLP-1 drugs in curbing addictive behavior may explain their spectacular success in treating obesity, a chronic disease state that many have suggested is indeed a food addiction disorder.
Our study demonstrated a reduced risk of suicidal thoughts and self-harm among people using GLP-1 drugs. This finding is particularly significant given earlier reports of suicidal thoughts and self-injury in people using GLP-1 drugs. In response to those reports, the European Medicines Agency conducted a review of all available data and concluded that there was no evidence of increased risk of suicidality in people using GLP-1 drugs.
In addition to the well-documented effects of GLP-1 drugs in reducing risks of adverse cardiovascular and kidney outcomes, our study shows a significant effect in reducing risk of blood clotting as well as deep vein thrombosis and pulmonary embolism.
One puzzling finding in our study is the reduced risk of infectious diseases such as pneumonia and sepsis. Our data complements another recent study that came to a similar conclusion showing that GLP-1 drugs reduced risk of cardiovascular death and death due to infectious causes, primarily COVID-19.
This is especially important since COVID-19 is regarded as a significant cardiovascular risk factor. Whether GLP-1 drugs completely offset the increased risk of cardiovascular disease associated with COVID-19 needs to be thoroughly evaluated.
Despite their broad therapeutic potential, GLP-1 drugs are not without risks.
Gastrointestinal issues, such as nausea, vomiting, constipation and gastroesophageal reflux disease are among the most common adverse effects associated with GLP-1 drugs.
Our study also identified other risks, including low blood pressure, sleep problems, headaches, formation of kidney stones, and gall bladder disease and diseases associated with the bile ducts. We also saw increased risks of drug-induced inflammation of the kidneys and pancreas – both serious conditions that can result in long-term health problems. These findings underscore the importance of careful monitoring in people who are taking GLP-1 medications.
A significant challenge with using GLP-1 drugs is the high rates at which patients stop using them, often driven by their exorbitant cost or the emergence of adverse effects. Discontinuation can lead to rapid weight gain.
That’s a problem, because obesity is a chronic disease. GLP-1 drugs provide effective treatment but do not address the underlying causes of obesity and metabolic dysfunction. As a result, GLP-1 drugs need to be taken long term to sustain their effectiveness and prevent rebound weight gain.
In addition, many questions remain about the long-term effectiveness and risks of these drugs as well as whether there are differences between GLP-1 formulations. Addressing these questions is critical to guide clinical practice.
Attitudes toward Christian nationalism don’t just boil down to views on race, religion and history − research suggests ‘moral foundations’ play a critical role
theconversation.com – Kerby Goff, Associate Director of Research at the Boniuk Institute for the Study and Advancement of Religious Tolerance, Rice University – 2025-01-22 07:43:00
The concept of Christian nationalism has taken center stage in many Americans’ minds as either the greatest threat to democracy or its only savior.
Political scientist Eric McDaniel defines Christian nationalism as the belief that the United States was founded to be a Christian nation. “In this view,” according to McDaniel, “America can be governed only by Christians, and the country’s mission is directed by a divine hand.” Why does the idea resonate with some but alarm others?
Scholars often portray Christian nationalism as rooted in a deep-seated desire to exclude non-Christians and people of color from American society. Historians point to a persistent link between racism and Christian nationalism among white Americans throughout U.S. history.
White Christians, however, are not the only ones sympathetic to Christian nationalist ideas. Nearly 40% of Black Protestants and 55% of Hispanic Protestants agree with statements such as “being Christian is an important part of being truly American.” Interestingly, over one-third of Muslims agree that the U.S. government should promote Christian moral values but not make it the official religion.
While racial, religious and political tribalism appear to influence who supports and who rejects Christian nationalism, our own research suggests there are other factors at play, specifically moral differences. We set out to understand the role that different moral values play in shaping support for and opposition to Christian nationalism.
Our study drew on the most influential social science approach to understanding moral values: moral foundations theory.
Moral differences
Moral foundations theory states that humans evolved to possess six primary moral intuitions that shape moral judgments – care for the vulnerable, fairness in how people are treated, loyalty to in-groups, respect for authority, reverence for the sacred, and the safeguarding of individual liberty.
Conservatives, on the other hand, tend to score equally on all six foundations. This suggests their moral judgments often involve balancing a desire to be compassionate with a desire to safeguard the stability of the social order.
For example, research finds that prioritizing care for the vulnerable, which is most pronounced among liberals, is linked to reduced acceptance of police use of force. Conservatives, who also value respect for authority, often favor “law and order” even when it involves use of force.
What our research found
With moral foundations theory as our guide, we analyzed Christian nationalism using a 2021 national survey of 1,125 U.S. adults conducted by YouGov, a global opinion research organization. We measured respondents’ moral foundations with the moral foundations questionnaire, which has been used extensively by researchers across numerous academic disciplines.
To measure Christian nationalism, we asked respondents whether they agreed with six questions, such as whether the federal government should declare the United States a Christian nation, advocate Christian values, allow prayer in public schools and allow religious symbols in public spaces, to list a few.
Support for Christian nationalism was most strongly linked to the moral foundations of loyalty, sanctity and liberty, but not to the authority foundation. We expected Christian nationalism to appeal to individuals who are enamored of authority, providing a rationale to their support for authoritarian leaders. But in our study, respect for authority did not distinguish those who supported Christian nationalism from those who opposed it.
We also found that support for Christian nationalism was linked to having a weaker fairness foundation. But it was not related to the strength of one’s care foundation.
We conclude that differences over Christian nationalism emerge not because some people care about the harm Christian nationalism could bring to non-Christian Americans, while others don’t. Rather, our findings suggest that those who support Christian nationalism do so because they are more sensitive to violations of loyalty, sanctity and liberty, and less sensitive to violations of fairness.
Our findings also revealed that support for Christian nationalism isn’t merely about racism or being ultrareligious, as critics often suggest. We accounted for endorsements of anti-Black stereotypes and religiosity. Yet, moral foundations remained the best predictors of Christian nationalist beliefs, even after taking into account these critical variables.
2 moral approaches to Christianity in the US
The Christian nationalism scale we and others have used combinesseveral different beliefs about Christianity’s role in society. So we also examined how each of the six items in our Christian nationalism scale related to each of the six moral foundations. We found two important patterns.
First, we found that the Christian nationalist desire to bring church and state closer together was most prominent among those with strong loyalty and sanctity foundations and a weak fairness foundation. This means that people who advocate for a Christian state largely do so out of loyalty – specifically, loyalty to God – and out of a desire to adhere to God’s requirements for society, as they understand them.
In line with this, support is also linked to a desire to protect the sanctity of the nation’s Christian heritage. Those who oppose bringing church and state closer together do so out of a sense that such a union would be unfair.
Second, we found that the desire to allow prayer in schools and religious symbols in public spaces was strongest among those with pronounced liberty and sanctity moral foundations. This likely means that people who favor public religious expression, but not a union of church and state, do so because they see individual religious expression as a sacred national ideal.
All in all, our study shows that support for or opposition to Christian nationalism is not merely due to religious, political or racial identities and prejudices, as many believe, but is rather due to entrenched moral differences between the two camps.
Building solidarity through diverse moral concerns
Moral divides are not necessarily impassable. It’s possible that understanding these diverging moral concerns may help build bridges between those who are sympathetic to and those who are skeptical toward Christian nationalism.
America’s founders conceived of fairness and liberty as central to a democratic society. And these values have fueled loyalty to a robust national identity ever since.
Our research suggests that the controversy surrounding Christian nationalism is driven not by a lack of moral concern by sympathizers or critics but by their different moral priorities. We believe that understanding such differences as morally rooted can open the door for mutual understanding and productive debate.