20 Of The Most Moving, Shocking And Incredible Stories HuffPost Has Published In The Last 20 Years

HuffPost turns 20 this year. To celebrate, we’re looking back at some of our most iconic work — the pieces that shocked us, surprised us and truly made us see the world in a different way. Take a look below. And if you have an all-time favourite story we’ve published over the years, share it in the comments!

I Don’t Know How To Explain To You That You Should Care About Other People

By Kayla Chadwick

@SpeakerRyan

Like many Americans, I’m having politics fatigue. Or, to be more specific, arguing-about-politics fatigue.

I haven’t run out of salient points or evidence for my political perspective, but there is a particular stumbling block I keep running into when trying to reach across the proverbial aisle and have those “difficult conversations” so smugly suggested by think piece after think piece:

I don’t know how to explain to someone why they should care about other people.

Read the full piece here.

FML: Why Millennials Are Facing The Scariest Financial Future Of Any Generation Since The Great Depression

By Michael Hobbes

We’ve all heard the statistics. More millennials live with their parents than with roommates. We are delaying partner-marrying and house-buying and kid-having for longer than any previous generation. And, according to The Olds, our problems are all our fault: We got the wrong degree. We spend money we don’t have on things we don’t need. We still haven’t learned to code. We killed cereal and department stores and golf and napkins and lunch. Mention “millennial” to anyone over 40 and the word “entitlement” will come back at you within seconds, our own intergenerational game of Marco Polo.

This is what it feels like to be young now. Not only are we screwed, but we have to listen to lectures about our laziness and our participation trophies from the people who screwed us.

Dying To Be Free: There’s A Treatment For Heroin Addiction That Actually Works. Why Aren’t We Using It?

By Jason Cherkis

The last image we have of Patrick Cagey is of his first moments as a free man. He has just walked out of a 30-day drug treatment center in Georgetown, Kentucky, dressed in gym clothes and carrying a Nike duffel bag. The moment reminds his father of Patrick’s graduation from college, and he takes a picture of his son with his cell phone. Patrick is 25. His face bright, he sticks his tongue out in embarrassment. Four days later, he will be dead from a heroin overdose.

‘For The Record, I Am Not Pregnant. What I Am Is Fed Up’

By Jennifer Aniston

Michael Buckner via Getty Images

Let me start by saying that addressing gossip is something I have never done. I don’t like to give energy to the business of lies, but I wanted to participate in a larger conversation that has already begun and needs to continue. Since I’m not on social media, I decided to put my thoughts here in writing.

For the record, I am not pregnant. What I am is fed up. I’m fed up with the sport-like scrutiny and body shaming that occurs daily under the guise of “journalism,” the “First Amendment” and “celebrity news.”

Together Alone: The Epidemic of Gay Loneliness

By Michael Hobbes

“I used to get so excited when the meth was all gone.”

This is my friend Jeremy.

“When you have it,” he says, “you have to keep using it. When it’s gone, it’s like, ‘Oh good, I can go back to my life now.’ I would stay up all weekend and go to these sex parties and then feel like shit until Wednesday. About two years ago I switched to cocaine because I could work the next day.”

The Mom Stays In The Picture

By Allison Tate

Last weekend, my family traveled to attend my oldest niece’s Sweet Sixteen party. My brother and sister-in-law planned this party for many months and intended it to be a big surprise, and it included a photo booth for the guests.

I showed up to the party a bit late and, as usual, slightly askew from trying to dress myself and all my little people for such a special night out. I’m still carrying a fair amount of baby weight and wearing a nursing bra, and I don’t fit into my cute clothes. I felt awkward and tired and rumpled.

Beyond The Battlefield: HuffPost’s Pulitzer Prize-Winning Series On Soldiers Severely Wounded In Iraq And Afghanistan

By David Wood

David Wood

Starting today, The Huffington Post begins a ten-part series, Beyond the Battlefield ― an exploration of the physical and emotional challenges, victories and setbacks that catastrophically wounded soldiers encounter after returning home from the battlefields of Iraq and Afghanistan.

Beyond the Battlefield is the result of several months of reporting and scores of interviews by the HuffPost’s veteran military correspondent, David Wood. It is a deeply-felt, hard-won and wide-ranging exploration of what it means for a soldier to suffer extraordinary, disabling wounds ― and how friends, families, and hometowns, as well as the military and medical communities, adjust and respond to the physical and emotional struggles these wounded warriors endure.

Everything You Know About Obesity Is Wrong

By Michael Hobbes

Finlay MacKay

Which brings us to one of the largest gaps between science and practice in our own time. Years from now, we will look back in horror at the counterproductive ways we addressed the obesity epidemic and the barbaric ways we treated fat people — long after we knew there was a better path.

The 21st Century Gold Rush: How The Refugee Crisis Is Changing The World Economy

By Malia Politzer and Emily Kassie

Emily Kassie

The biggest refugee crisis in recorded history has engulfed continents, swung elections and fueled the rise of nativism. It has also made a lot of people very, very rich. These are the stories of the CEOs, criminal masterminds, pencil-pushers and low-flying vultures who have figured out how to profit from global instability, also known as human suffering.

What Bullets Do To Bodies

By Jason Fagone

The first thing Dr. Amy Goldberg told me is that this article would be pointless. She said this on a phone call last summer, well before the election, before a tangible sensation that facts were futile became a broader American phenomenon. I was interested in Goldberg because she has spent 30 years as a trauma surgeon, almost all of that at the same hospital, Temple University Hospital in North Philadelphia, which treats more gunshot victims than any other in the state and is located in what was, according to one analysis, the deadliest of the 10 largest cities in the country until last year, with a homicide rate of 17.8 murders per 100,000 residents in 2015.

Over my years of reporting here, I had heard stories about Temple’s trauma team. A city prosecutor who handled shooting investigations once told me that the surgeons were able to piece people back together after the most horrific acts of violence. People went into the hospital damaged beyond belief and came walking out.

Existing While Black: What Does It Feel Like When Every Move You Make Is Policed?

Edited by Taryn Finley

Jo Etta M. Harris was nursing her child in her car before a family outing. Gil Perkins was talking on the phone outside of his home. Kelly Shepard’s boys were shopping for video games. And in each instance, someone saw them as suspicious or a threat and called the police.

This isn’t new. It happens every day. The experiences of Harris, Perkins, Shepard – and so many others – are reminders that black people don’t have the privilege to simply exist in peace.

The Persuaders

By Dave Jamieson

Zoe Van Dijk for HuffPost

Every week, American employers hire labor consultants to prevent their workers from organizing. Known legally as “persuaders,” these consultants play a crucial role in keeping U.S. union membership near a historic low — and they are well rewarded for their efforts. Many now earn more than $2,000 per day.

HuffPost has produced a series of stories revealing who these consultants are, where they come from and what they do. The reporting is based primarily on documents obtained through dozens of public record requests. We hope these stories shed light on a trade that’s plied primarily in the shadows but impacts workplaces around the country.

This Is Why Poor People’s Bad Decisions Make Perfect Sense

By Linda Tirado

Linda Tirado

There’s no way to structure this coherently. They are random observations that might help explain the mental processes. But often, I think that we look at the academic problems of poverty and have no idea of the why. We know the what and the how, and we can see systemic problems, but it’s rare to have a poor person actually explain it on their own behalf. So this is me doing that, sort of.

What Is Hamas Thinking Now?

By Akbar Shahid Ahmed

Akbar Shahid Ahmed / HuffPost

DOHA, Qatar ― Six months into a war Hamas started ― with more than 33,000 Palestinians dead, more succumbing to famine daily and Israel determined to continue its aggressive campaign against the organization with robust American military support ― the militant group says it is confident it will wield significant influence in the future, come what may in Gaza.

Sandra Bland Died One Year Ago: And Since Then, At Least 810 People Have Lost Their Lives In Jail

By Dana Liebelson & Ryan J. Reilly

Sandra Bland/Facebook

What made Bland’s death so shocking — the reason that millions of people watched the dash-cam footage of her arrest or closely examined her mugshot—was the mystery at its heart. What had really happened inside the Waller County jail? If Bland had taken her own life, how could she have reached a state of irreversible despair so suddenly?

Kip Kinkel Is Ready To Speak

By Jessica Schulberg

Mike McQuade for HuffPost

That image of Kinkel has remained frozen in time: the dangerous child people point to as the reason some kids need to be locked up for life. For decades, Kinkel never tried to correct it. He refused every interview request and even avoided being photographed in group activities inside the prison. He worried that reemerging publicly would only further traumatize his victims. But last year he agreed to speak to HuffPost.

The Super Predators: When The Man Who Abuses You Is Also A Cop

By Melissa Jeltsen and Dana Liebelson

All Sarah Loiselle wanted was a carefree summer. There was no particular reason she was feeling restless, but she’d been single for about a year and her job working with cardiac patients in upstate New York could be intense. So when she learned that a Delaware hospital needed temporary nurses, she leapt at the chance to spend a summer by the beach. In June 2011, the tall, bubbly 32-year-old drove her Jeep into the sleepy coastal town of Lewes. She and her poodle, Aries, moved into a rustic apartment above a curiosity shop that once housed the town jail. The place was so close to the bay that she could go sunbathing on her days off. It didn’t bother Loiselle that she’d be away from her friends and family for a while: She felt like she’d put her real life on hold, that she was blissfully free of all her responsibilities.

Lorena Bobbitt Is Done Being Your Punchline

By Melissa Jeltsen

Melissa Jeltsen/HuffPost

On a recent trip to Target, Lorena Bobbitt struggled to use the computer at the digital photo center. She was trying, unsuccessfully, to put her 11-year-old daughter’s picture on a Christmas card. A young male employee came over to help. When they were done and she was typing in her first name for payment, he audibly gasped.

“I thought the machine must be broken,” she recalled. “But he said, ‘I know who you are!’”

Jerry And Marge Go Large

By Jason Fagone

Gerald Selbee broke the code of the American breakfast cereal industry because he was bored at work one day, because it was a fun mental challenge, because most things at his job were not fun and because he could—because he happened to be the kind of person who saw puzzles all around him, puzzles that other people don’t realise are puzzles: the little ciphers and patterns that float through the world and stick to the surfaces of everyday things.

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Trump Administration Is ‘Actively Looking’ At Suspending Constitutional Right, Says Aide

During a press appearance on Friday, Trump senior adviser Stephen Miller detailed another possible prong of the White House’s attempts to target unauthorised immigrants: suspending habeas corpus.

“The Constitution is clear — and that of course is the supreme law of the land — that the privilege of the writ of habeas corpus can be suspended in a time of invasion,” Miller said. “So it’s an option that we’re actively looking at.”

Habeas corpus – as enshrined in the Constitution – helps shield people from unlawful detention, and ensures that they’re able to contest their incarceration in court. It translates to “you should have the body” in Latin and guarantees that individuals are able to physically appear in front of a judge if they are detained.

Any suspension of habeas corpus would further undercut due process protections for individuals who are detained by the Trump administration as the White House seeks to ramp up immigrant deportations.

The administration has already tried to invoke the Alien Enemies Act – a law that allows the White House to remove immigrants from the US without a hearing – in order to justify the deportation of alleged Venezuelan gang members to a maximum security prison in El Salvador.

Miller’s comments on Friday signalled an openness to expanding upon these actions if the courts – which have thus far blocked a number of Trump’s immigration policies – continue to stymie the White House’s goals.

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Fat-rich fluid fuels immune failure in ovarian cancer

New research led by Irish scientists has uncovered how lipid-rich fluid in the abdomen, known as ascites, plays a central role in weakening the body’s immune response in advanced ovarian cancer. The findings offer new insights into immune suppression in ovarian cancer and open promising avenues for future immunotherapy approaches.

Over 70% of patients with ovarian cancer are diagnosed at an advanced stage, often presenting with large volumes of ascites. This ascites fluid not only supports the spread of cancer throughout the abdominal cavity but also significantly impairs the body’s immune defences. Understanding how ascites affects the immune system is important for developing better treatments that use the immune system to fight cancer.

In this recent study, researchers from Trinity College Dublin and University College Dublin explored how ascites disrupts immune cell function, with a particular focus on natural killer (NK) cells and T cells, which are key players in the body’s ability to eliminate tumours.

By analysing the contents of ascites fluid from ovarian cancer patients, the team identified a group of fat molecules called phospholipids as key drivers of this immune dysfunction.

Dr Karen Slattery, Research Fellow in the Trinity Translational Medicine Institute, is the first author of the research article just published in leading international journal Science Immunology. She said: “We found that these lipids interfere with NK cell metabolism and suppress their ability to kill cancer cells. Crucially, we also discovered that blocking the uptake of these phospholipids into NK cells using a specific receptor blocker can restore their anti-tumour activity, which offers a compelling new target for therapeutic intervention.”

“This work adds a critical piece to the puzzle of why ovarian cancer is so aggressive and has such poor outcomes. While the immune system is naturally equipped to detect and destroy cancer cells, this function is switched off in many individuals with ovarian cancer, and we now know that this is in part due to the fat-rich environment created by ascites.”

Prof. Lydia Lynch, formerly based in Trinity and now in Princeton University, is the senior author of the research article. She said: “This study marks a significant advancement in ovarian cancer research, identifying a new mechanism underpinning immune failure and laying the foundation for new therapies that could restore immune function in these patients. By targeting the fat-induced suppression of immune cells, future treatments could empower the body’s own immune defences to fight back and in doing so, improve outcomes for ovarian cancer patients.”

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The origins of language

Chimpanzees are capable of complex communication: The human capacity for language may not be as unique as previously thought. Chimpanzees have a complex communication system that allows them to combine calls to create new meanings, similar to human language. Combining calls creatively: Chimpanzees use four ways to change meaning when combining single calls into two-call combinations, including compositional and non-compositional combinations, and they use a large variety of call combinations in a wide range of contexts.

Humans are the only species on earth known to use language. They do this by combining sounds into words and words into sentences, creating infinite meanings. This process is based on linguistic rules that define how the meaning of calls is understood in different sentence structures. For example, the word “ape” can be combined with other words to form compositional sentences that add meaning: “the ape eats” or append meaning: “big ape,” and non-compositional idiomatic sentences that create a completely new meaning: “go ape.” A key component of language is syntax, which determines how the order of words affects meaning, for instance how “go ape” and “ape goes” convey different meanings.

One fundamental question in science is to understand where this extraordinary capacity for language originates from. Researchers often use the comparative approach to trace the evolutionary origins of human language by comparing the vocal production of other animals, particularly primates, with that of humans. Unlike humans, other primates typically rely on single calls (referred to as call types), and while some species combine calls, these combinations are only a few per species and mostly serve to alert others to the presence of predators. This suggests that their communication systems may be too restricted to be a precursor to the complex, open-ended combinatorial system that is human language. However, we may not have a full picture of the linguistic capacities of our closest living relatives, particularly how they might use call combinations to significantly expand their meaning.

Studying the meaning of chimpanzee vocalisations

Researchers from the Max Planck Institutes for Evolutionary Anthropology and for Cognitive and Brain Sciences in Leipzig, Germany, and from the Cognitive Neuroscience Center Marc Jeannerod (CNRS/Université Claude Bernard Lyon 1) and Neuroscience Research Center (CNRS/Inserm/Université Claude Bernard Lyon 1) in Lyon, France recorded thousands of vocalisations from three groups of wild chimpanzees in the Taï National Park in Ivory Coast. They examined how the meanings of 12 different chimpanzee calls changed when they were combined into two-call combinations. “Generating new or combined meanings by combining words is a hallmark of human language, and it is crucial to investigate whether a similar capacity exists in our closest living relatives, chimpanzees and bonobos, in order to decipher the origins of human language,” says Catherine Crockford, senior author of the study. “Recording chimpanzee vocalisations over several years in their natural environment is essential in order to document their full communicative capabilities, a task that is becoming increasingly challenging due to growing human threats to wild chimpanzee populations,” says Roman Wittig, co-author of the study and director of the Taï Chimpanzee Project.

Chimpanzees’ complex communication system

The study reveals four ways in which chimpanzees alter meanings when combining single calls into 16 different two-call combinations, analogous to the key linguistic principles in human language. Chimpanzees used compositional combinations that added meaning (e.g., A = feeding, B = resting, AB = feeding + resting) and clarified meaning (e.g., A = feeding or travelling, B = aggression, AB = travelling). They also used non-compositional idiomatic combinations that created entirely new meanings (e.g., A = resting, B = affiliation, AB = nesting). Crucially, unlike previous studies which have mostly reported call combinations in limited situations such as predator encounters, the chimpanzees in this study expanded their meanings through the versatile combination of most of their single calls into a large diversity of call combinations used in a wide range of contexts.

“Our findings suggest a highly generative vocal communication system, unprecedented in the animal kingdom, which echoes recent findings in bonobos suggesting that complex combinatorial capacities were already present in the common ancestor of humans and these two great ape species,” says Cédric Girard-Buttoz, first author on the study. He adds: “This changes the views of the last century which considered communication in the great apes to be fixed and linked to emotional states, and therefore unable to tell us anything about the evolution of language. Instead, we see clear indications here that most call types in the repertoire can shift or combine their meaning when combined with other call types. The complexity of this system suggests either that there is indeed something special about hominid communication — that complex communication was already emerging in our last common ancestor, shared with our closest living relatives — or that we have underestimated the complexity of communication in other animals as well, which requires further study.”

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First fossil evidence of endangered tropical tree discovered

For the first time, scientists have discovered fossil evidence of an endangered, living tropical tree species. The unprecedented find was made in Brunei, a country on the large island of Borneo, and reveals a critical piece of the ancient history of Asia’s rainforests, highlighting the urgent need for conservation in the region, according to researchers at Penn State who led the discovery.

The research team published their findings in the American Journal of Botany.

The fossils, at least two million years old, represent the first direct evidence of an endangered tropical tree species in the fossil record. The research study, conducted in collaboration with the University of Brunei among other international partners, identified fossilized leaves of Dryobalanops rappa, known locally as the Kapur Paya. It is a towering dipterocarp tree that still exists today but is endangered and found in the carbon-rich peatlands of Borneo, including Brunei.

“This discovery provides a rare window into the ancient history of Asia’s wet tropical forests,” said Tengxiang Wang, a doctoral student in the College of Earth and Mineral Sciences at Penn State and lead author on the paper. “We now have fossil proof that this magnificent tree species has been a dominant part of Borneo’s forests for millions of years, emphasizing its ecological importance and the need to protect its remaining habitats.”

Until now, the fossil record of Asia’s wet tropical forests has been surprisingly scarce compared to the Amazon and Africa, said Peter Wilf, professor of geosciences at Penn State and co-author.

The team identified the fossils by analyzing microscopic features of the preserved leaf cuticles, which revealed a perfect match with modern Dryobalanops rappa, down to the last cellular detail.

“Our findings highlight that these forests are not just rich in biodiversity today but have been home to iconic tree species for millions of years,” Wang said. “Conserving them is not only about protecting present-day species but also about preserving a legacy of ecological resilience that has withstood millions of years.”

Dipterocarps, the dominant tree family in Asia’s rainforests, are critical for carbon storage and biodiversity. However, the researchers said, they are increasingly threatened by deforestation and habitat destruction. By revealing the deep historical roots of these trees, this discovery adds an important new perspective to conservation efforts.

“The findings add a new dimension to conservation; we are not only protecting modern species but ancient survivors that have been key components of their unique ecosystems for millions of years,” Wang said. “This historical perspective makes both the endangered trees and their habitats even more valuable for conservation. Our study also shows how fossil evidence can strengthen conservation strategies for threatened species and ecosystems based on their historical significance.”

Understanding the history of tropical forests is essential for their conservation, especially as many key species face rapid decline, Wilf said.

“Penn State’s paleobotany group is making exciting fossil discoveries with our international partners in several Southeast Asian countries, illuminating the poorly known history of the region’s magnificent and severely threatened tropical forests,” Wilf said. “Our finding fossils of living, endangered, giant tree species provides a vital historical foundation for conserving tropical Asia’s keystone trees, the rapidly disappearing dipterocarps.”

Two collaborators on the paper are Penn State alumni: Michael Donovan, The Field Museum; and Xiaoyu Zou, University of California San Diego. Additionally, collaborators from other institutions include Antonino Briguglio, Università degli Studi di Genova; László Kocsis, University of Lausanne; and Ferry Silk, Universiti Brunei Darussalam.

The research was supported by the U.S. National Science Foundation, Universiti Brunei Darussalam research grants and a Penn State Institute of Energy and the Environment seed grant.

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Ultrasound unlocks a safer, greener way to make hydrogels

Researchers at McGill University, in collaboration with Polytechnique Montréal, pioneered a new way to create hydrogels using ultrasound, eliminating the need for toxic chemical initiators. This breakthrough offers a faster, cleaner and more sustainable approach to hydrogel fabrication, and produces hydrogels that are stronger, more flexible and highly resistant to freezing and dehydration. The new method also promises to facilitate advances in tissue engineering, bioadhesives and 3D bioprinting.

Hydrogels are gels composed of polymers that can absorb and retain large amounts of water. They are widely used in wound dressings, drug delivery, tissue engineering, soft robotics, soft contact lenses and more.

Gel formation within minutes

Traditional hydrogel manufacturing relies on chemical initiators, some of which can be harmful, particularly in medical applications. Initiators are the chemicals used to trigger chemical chain reactions. The McGill research team, led by Mechanical Engineering Professor Jianyu Li, has developed an alternative method using ultrasound. When applied to a liquid precursor, sound waves create microscopic bubbles that collapse with immense energy, triggering gel formation within minutes.

“The problem we aimed to solve was the reliance on toxic chemical initiators,” said Li. “Our method eliminates these substances, making the process safer for the body and better for the environment.”

This ultrasound-driven technique is dubbed “sonogel.”

“Typical hydrogel synthesis can take hours or even overnight under UV light,” said Li. “With ultrasound, it happens in just five minutes.”

Revolutionizing biomedical applications

One of the most exciting possibilities for this technology is in non-invasive medical treatments. Because ultrasound waves can penetrate deep into tissues, this method could enable in-body hydrogel formation without surgery.

“Imagine injecting a liquid precursor and using ultrasound to solidify it precisely where needed,” said Li. “This could be a game-changer for treating tissue damage and regenerative medicine. Further refinement, we can unlock new possibilities for safer, greener material production.”

The technique also opens the door to ultrasound-based 3D bioprinting. Instead of relying on light or heat, researchers could use sound waves to precisely “print” hydrogel structures.

“By leveraging high-intensity focused ultrasound, we can shape and build hydrogels with remarkable precision,” said Jean Provost, one of co-authors of the study and assistant professor of engineering physics at Polytechnique Montréal.

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Antibiotics from human use are contaminating rivers worldwide, study shows

Millions of kilometres of rivers around the world are carrying antibiotic pollution at levels high enough to promote drug resistance and harm aquatic life, a McGill University-led study warns.

Published in PNAS Nexus, the study is the first to estimate the scale of global river contamination from human antibiotics use. Researchers calculated that about 8,500 tonnes of antibiotics — nearly one-third of what people consume annually — end up in river systems around the world each year even after in many cases passing through wastewater systems.

“While the amounts of residues from individual antibiotics translate into only very small concentrations in most rivers, which makes them very difficult to detect, the chronic and cumulative environmental exposure to these substances can still pose a risk to human health and aquatic ecosystems,” said Heloisa Ehalt Macedo, a postdoctoral fellow in geography at McGill and lead author of the study.

The research team used a global model validated by field data from nearly 900 river locations. They found that amoxicillin, the world’s most-used antibiotic, is the most likely to be present at risky levels, especially in Southeast Asia, where rising use and limited wastewater treatment amplify the problem.

“This study is not intended to warn about the use of antibiotics — we need antibiotics for global health treatments — but our results indicate that there may be unintended effects on aquatic environments and antibiotic resistance, which calls for mitigation and management strategies to avoid or reduce their implications,” said Bernhard Lehner, a professor in global hydrology in McGill’s Department of Geography and co-author of the study.

The findings are especially notable because the study did not consider antibiotics from livestock or pharmaceutical factories, both of which are major contributors to environmental contamination.

“Our results show that antibiotic pollution in rivers arising from human consumption alone is a critical issue, which would likely be exacerbated by veterinarian or industry sources of related compounds” said Jim Nicell, an environmental engineering professor at McGill and co-author of the study. “Monitoring programs to detect antibiotic or other chemical contamination of waterways are therefore needed, especially in areas that our model predicts to be at risk.”

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A more realistic look at DNA in action

By creating a more true-to-life representation of DNA’s environment, researchers at Northwestern University have discovered that strand separation — the essential process a “resting” double helix undergoes before it can initiate replication or make repairs — may take more mechanical force than the field previously believed.

Most biochemistry labs that study DNA isolate it within a water-based solution that allows scientists to manipulate DNA without interacting with other molecules. They also tend to use heat to separate strands, heating the DNA to over 150 degrees Fahrenheit, a temperature a cell would never naturally reach. By contrast, in a living cell DNA lives in a very crowded environment, and special proteins attach to DNA to mechanically unwind the double helix and then pry it apart.

“The interior of the cell is super crowded with molecules, and most biochemistry experiments are super uncrowded,” said Northwestern professor John Marko. “You can think of extra molecules as billiard balls. They’re pounding against the DNA double helix and keeping it from opening.”

Marko, a professor of molecular biosciences as well as physics in Northwestern’s Weinberg College of Arts and Sciences, led the research along with Northwestern post-doctoral researcher Parth Desai. In Marko’s lab, for their experiments, he and Desai use microscopic magnetic tweezers to separate DNA and then carefully attach strands of it to surfaces on one end, and tiny magnetic particles on the other, then conduct high-tech imaging. The technology has been around for 25 years, and Marko was one of the first researchers theorizing about and then using it.

Marko and Desai wrote the paper that not only identifies but quantifies the amount of stress imposed by crowding, that will be published on June 17 in the Biophysical Journal.

Desai introduced three types of molecules to the solution holding DNA to mimic proteins and investigated interactions among glycerol, ethylene glycol and polyethylene glycol (each approximately the size of one DNA double helix, two or three nanometers).

“We wanted to have a wide variety of molecules where some cause dehydration, destabilizing DNA mechanically, and then others that stabilize DNA,” Desai said. “It’s not exactly analogous to things found in cells, but you could imagine that other competing proteins in cells will have a similar effect. If they’re competing for water, for instance, they would dehydrate DNA, and if they’re not competing for water, they would crowd the DNA and have this entropic effect.”

While fundamental, research like this has “been the basis for many, many, many medical advances,” Marko said, such as deep sequencing of DNA, where scientists can now sequence an entire human genome in under a day. He also thinks their findings may be broadly applicable to other elements of fundamental biochemical processes.

“If this affects DNA strand separation, all protein interactions with DNA are also going to be affected,” Marko said. “For example, the tendency for proteins to stick to specific sites on DNA and to control specific processes — this is also going to be altered by crowding.”

In addition to running more experiments that incorporate multiple crowding agents, the team hopes to move closer to a true representation of a cell, and from there, study how interactions between enzymes and DNA are impacted by crowding.

This work was supported by the National Institutes of Health (grant R01-GM105847) and by subcontract to the University of Massachusetts Center for 3D Structure and Physics of the Genome (under NIH grant UM1-HG011536).

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Computing: Shedding light on shadow branches

What happens when trailblazing engineers and industry professionals team up? The answer may transform the future of computing efficiency for modern data centers.

Data centers house and use large computers to run massive amounts of data. Oftentimes, the processors can’t keep up with this workload because it’s taxing to predict and prepare instructions to carry out. This slows the flow of data. Thus, when you type a question into a search engine, the answer generates more slowly or doesn’t provide the information you need.

To remedy this issue, researchers at Texas A&M University developed a new technique called Skia in collaboration with Intel, AheadComputing, and Princeton to help computer processors better predict future instructions and improve computing performance.

The team includes Dr. Paul V. Gratz, a professor in the Department of Electrical and Computer Engineering, Dr. Daniel A. Jiménez, a professor in the Department of Computer Science and Engineering, and Chrysanthos Pepi, a graduate student in the Department of Electrical and Computer Engineering.

“Processing instructions has become a major bottleneck in modern processor design,” Gratz said. “We developed a new technique, Skia, to better predict what’s coming next and alleviate that bottleneck.”

A common problem for modern data center workloads is that the instruction stream — the steps a computer must take for processing — can be too large or difficult to process. Skia, a Greek word for shadow, can not only help better predict future instructions, but based upon that information, it can improve the throughput of instructions on the system. Throughput refers to units of completed processing per units of time.

“Think of throughput in terms of being a server in a restaurant,” Gratz said. “You have lots and lots of jobs to do. How many tasks can you complete, or how many instructions can you execute per unit time? You want high throughput, especially for computing.”

Improving throughput can lead to quicker performance and less power consumption for the data center.

“There are new bottlenecks in data center workloads associated with the instruction footprint and by fixing these, we can make the hardware better mapped and suited to that workload,” Gratz added. “If we make it up to 10% more efficient, a company previously needing to make 100 data centers around the country, now only needs to make 90, which is 10 less data centers. That’s pretty significant. These data centers cost millions of dollars, and they consume roughly the equivalent of the entire output of a power plant.”

In data centers, modern processors improve efficiency by predicting instructions and retrieving them before they’re needed, relying on a system known as Fetch Directed Instruction Prefetching (FDIP). FDIP uses Branch Prediction Unit to anticipate and fetch instructions.

However, as data center applications grow more complex, issues can occur when the Branch Target Buffer (BTB), which helps to monitor and track instructions, faults. This hinders FDIPS’s effectiveness, causing incorrect predictions and cache pollution. Many of these missed branches, termed “Shadow Branches,” exist in previously fetched cache lines but aren’t being used by the current instruction sequence and remain undecoded.

Skia identifies and decodes these shadow branches in unused bytes, storing them in a memory area called the Shadow Branch Buffer, which can be accessed alongside the BTB.

“What makes this technique interesting is that most of the future instructions were already available, and we demonstrate that Skia, with a minimal hardware budget, can make data centers more efficient, nearly twice the performance improvement versus adding the same amount of storage to the existing hardware as we observe,” Pepi said.

Their findings, “Skia: Exposing Shadow Branches,” were published in one of the leading computer architecture conferences, the ACM International Conference on Architectural Support for Programming Languages and Operating Systems. The team also traveled to the Netherlands to present their work to colleagues from around the globe.

Other collaborators on the project include David I. August, a professor in the Department of Computer Science from Princeton University, Krishnam Tibrewala, a graduate student in the Computer Science and Engineering Department at Texas A&M, Gilles Pokam, a senior principal engineer at Intel Corporation, and Bhargav Reddy Godala and Gino Chacon, senior central processing unit architects at AheadComputing.

Funding for this research is administered by the Texas A&M Engineering Experiment Station (TEES), the official research agency for Texas A&M Engineering.

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A small bicycle handlebar sensor can help map a region’s riskiest bike routes

While things like rain or hills can keep people from cycling, a major impediment is the risk of getting hit by a car. It’s hard to identify the safest routes to ride, especially for beginner cyclists, and a key way to flag dicey streets involves time and injury: waiting until cars have hit several cyclists at a given location.

A University of Washington-led team has developed a system, called ProxiCycle, that logs when a passing car comes too close to a cyclist (within four feet). A small, inexpensive sensor plugs into bicycle handlebars and tracks the passes, sending them to the rider’s phone. The team tested the system for two months with 15 cyclists in Seattle and found a significant correlation between the locations of close passes and other indicators of poor safety, such as collisions. Deployed at scale, the system could support mapping or navigating cyclists on safer bike routes through cities.

“Experienced cyclists have this mental map of which streets are safe and which are unsafe, and I wanted to find a simple way to pass that knowledge down to novice cyclists,” said lead author Joseph Breda, a UW doctoral student in the Paul G. Allen School of Computer Science & Engineering. “Cycling is really good for your health and for the environment. Getting more people biking more often is how we reap those rewards and increase safety in numbers for cyclists on the roads.”

The team presented its research Apr. 29 at the ACM CHI Conference on Human Factors in Computing Systems in Yokohama, Japan.

To start, researchers surveyed 389 people in Seattle. Respondents of all cycling experience levels ranked the threat of cars as the factor which most discouraged them from cycling, and said they’d be very likely to use a map that helps navigate for safety. But a key factor preventing this is limited data on road safety.

The team then built a small sensor system that plugs into a bike’s left handlebar. The system, which costs less than $25 to build, consists of a 3D printed plastic casing that houses a pair of sensors and a Bluetooth antenna. The antenna transmits data to the rider’s phone, where the team’s algorithm susses out what’s a passing car rather than a person, or another cyclist, or a tree.

The team validated the system both by testing it in a parking lot, with a car passing at different distances, and with seven cyclists riding through Seattle with GoPro cameras on their handlebars. Researchers watched the footage from these rides and compared this to the sensor output.

The team then recruited 15 cyclists through the newsletter of Seattle Neighborhood Greenways, a local advocacy group. Each got a ProxiCycle sensor, a custom Android application and instructions. The cyclists took 240 bike rides over two months and recorded 2,050 close passes. Researchers then compared the locations of close passes with riders’ perceived safety at different locations in the city — which they measured by showing cyclists images of locations and having them rate how safe they felt at those locations (referred to as “perceived safety”) — and with the locations of known automobile-to-bike collisions in the last five years.

The team found a significant correlation between close passes and both other indicators of cycling risk. They also found that this measure of close passes was a better indicator of actual safety than the surveyed perceived safety, which is the current standard used by policymakers to study safety when collisions aren’t enough.

In the future, researchers hope to scale the study up and potentially account for other risk factors, such as cyclists being hit by opening car doors, and deploy ProxiCylce in other cities. With enough data, existing bike mapping apps, such as Google Maps or Strava, might include safer route suggestions for cyclists.

Some of those routes involve only minor adjustments.

“One study participant, who was living down by Seattle Center, was biking down Mercer all the time,” Breda said. “It’s this busy, multi-lane road. But just before the study, they found out that there’s a great bike lane on a quieter street, just one block north.”

Keyu Chen, an applied science lead at Gridware, and Thomas Ploetz, a professor at Georgia Institute of Technology, are also co-authors on this paper. Shwetak Patel, a UW professor in the Allen School, is the senior author.

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