Latest news with #UniversityofArizona
Daily Maverick
a day ago
- Science
- Daily Maverick
New research strengthens case for age of ancient New Mexico footprints
Researchers used a technique called radiocarbon dating to determine that organic matter in the remains of wetland muds and shallow lake sediments near the fossilized foot impressions is between 20,700 and 22,400 years old. That closely correlates to previous findings, based on the age of pollen and seeds at the site, that the tracks are between 21,000 and 23,000 years old. The footprints, whose discovery was announced in 2021, indicate that humans trod the landscape of North America thousands of years earlier than previously thought, during the most inhospitable conditions of the last Ice Age, a time called the last glacial maximum. The age of the footprints has been a contentious issue. Asked how the new findings align with the previous ones, University of Arizona archaeologist and geologist Vance Holliday, the study leader, replied: 'Spectacularly well.' Homo sapiens arose in Africa roughly 300,000 years ago and later spread worldwide. Scientists believe our species entered North America from Asia by trekking across a land bridge that once connected Siberia to Alaska. Previous archaeological evidence had suggested that human occupation of North America started roughly 16,000 years ago. The hunter-gatherers who left the tracks were traversing the floodplain of a river that flowed into an ancient body of water called Lake Otero. The mud through which they walked included bits of semi-aquatic plants that had grown in these wetlands. Radiocarbon dating is used to determine the age of organic material based on the decay of an isotope called carbon-14, a variant of the element carbon. Living organisms absorb carbon-14 into their tissue. After an organism dies, this isotope changes into other atoms over time, providing a metric for determining age. 'Three separate carbon sources – pollen, seeds and organic muds and sediments – have now been dated by different radiocarbon labs over the course of the trackway research, and they all indicate a last glacial maximum age for the footprints,' said Jason Windingstad, a University of Arizona doctoral candidate in environmental science and co-author of the study published this week in the journal Science Advances. The original 2021 study dated the footprints using radiocarbon dating on seeds of an aquatic plant called spiral ditchgrass found alongside the tracks. A study published in 2023 used radiocarbon dating on conifer pollen grains from the same sediment layers as the ditchgrass seeds. But some scientists had viewed the seeds and pollen as unreliable markers for dating the tracks. The new study provides further corroboration of the dating while also giving a better understanding of the local landscape at the time. 'When the original paper appeared, at the time we didn't know enough about the ancient landscape because it was either buried under the White Sands dune field or was destroyed when ancient Lake Otero, which had a lot of gypsum, dried out after the last Ice Age and was eroded by the wind to create the dunes,' Holliday said. Today, the landscape situated just west of the city of Alamogordo consists of rolling beige-colored dunes of the mineral gypsum. 'The area of and around the tracks included water that came off the mountains to the east, the edge of the old lake and wetlands along the margins of the lake. Our dating shows that this environment persisted before, during and after the time that people left their tracks,' Holliday said. The area could have provided important resources for hunter-gatherers. 'We know from the abundant tracks in the area that at least mammoths, giant ground sloths, camels and dire wolves were around, and likely other large animals. Given the setting, there must have been a large variety of other animals and also plants,' Holliday added. The climate was markedly different than today, with cooler summers and the area receiving significantly more precipitation. 'It is important to note that this is a trackway site, not a habitation site,' Windingstad said. 'It provides us a narrow view of people traveling across the landscape. Where they were going and where they came from is obviously an open question and one that requires the discovery and excavation of sites that are of similar age in the region. So far, these have not been found.'
Time of India
a day ago
- Science
- Time of India
Who really were the first Americans? New study debunks earlier theory
A new study has reignited debate over the age of human footprints discovered at White Sands National Park in New Mexico. These ancient tracks, first revealed in 2021, were initially dated to between 21,000 and 23,000 years ago — suggesting humans lived in North America during the peak of the last Ice Age, far earlier than previously thought. To verify these findings, researchers led by Vance Holliday of the University of Arizona conducted fresh radiocarbon dating on organic sediments from core samples at the site. Their results aligned with the earlier estimates, placing the footprints firmly within the Last Glacial Maximum. The analysis, conducted in independent labs, adds weight to the theory that humans occupied the region around 23,000 years ago. "Our data supports the original data" that dated the site to 23,000 years ago, study first author Vance Holliday, a professor emeritus of anthropology and geosciences at the University of Arizona, told Live Science. "Plus, we now have an idea of what the landscape was like when people were out there." by Taboola by Taboola Sponsored Links Sponsored Links Promoted Links Promoted Links You May Like Access all TV channels anywhere, anytime Techno Mag Learn More Undo The footprints, likely left by Ice Age hunter-gatherers, suggest early migration via the Bering Land Bridge from Asia to North America. If confirmed, this would challenge the long-held belief that the Clovis people — who arrived around 13,000 years ago — were the first inhabitants of the Americas. Dating the tracks has proven controversial. In 2022, skeptics argued that radiocarbon dating of ditch grass (a water plant) may have yielded misleadingly old results due to underwater carbon contamination. To address this, researchers later used optically stimulated luminescence (OSL) and pollen-based radiocarbon methods, which again confirmed the original timeline. Live Events The latest study brings the total number of radiocarbon-dated samples from the footprint layer to 55, including mud, seeds, and pollen. 'It would be extreme serendipity for all these independent dates to be wrong,' Holliday said. Still, some experts remain cautious. Michael Waters of Texas A&M told Live Science that the source of the organic carbon is unclear and could still be affected by old water-derived carbon. He also pointed out the absence of associated artifacts or tools, though Holliday argues this is consistent with mobile hunter-gatherer behavior. Despite lingering doubts, the growing body of evidence points to a much earlier human presence in North America than previously accepted — a discovery that may reshape our understanding of the continent's earliest settlers.
Yahoo
2 days ago
- Health
- Yahoo
Researchers make concerning discovery in blood of firefighters and health care workers: 'Potential sources of exposure remain unclear'
There are heroes who put their lives and health on the line to protect others every day. We want those brave and selfless people to be celebrated and protected as much as possible, so it's a huge problem to discover that they're more at risk than we previously knew. Unfortunately, it turns out that firefighters and health care workers have above-average levels of toxic PFAS in their bodies, and we're not sure why, reported the University of Arizona. A recent study published in the Journal of Exposure Science & Environmental Epidemiology looked at the levels of multiple perfluoroalkyl and polyfluoroalkyl substances in the blood of various essential workers. It found that firefighters and health care workers had elevated levels of certain PFAS compared with other groups. The study had 1,960 participants, including 280 firefighters, 787 health care workers, and 734 other essential workers. It took place over three years. During that time, the overall level of PFAS in the blood samples studied declined but was still significant. "Our study reinforces previous research showing elevated PFAS levels among firefighters and suggests that health care workers may have unique sources of PFAS exposure as well," said senior author Kate Ellingson, a professor at the Mel and Enid Zuckerman College of Public Health, per the University of Arizona. "Our findings underscore the need to understand occupational exposure pathways for PFAS among different types of workers." PFAS are toxic substances also known as "forever chemicals" because they essentially never break down in the environment or the body. Instead, they build up. PFAS are used in a wide range of products, especially ones that are water- or stain-resistant. They pollute our water and soil and cause a wide range of serious health effects. "Almost all adults in the U.S. have detectable levels of certain PFAS, and people in occupations with more frequent exposure to PFAS-containing materials have been shown to exhibit higher serum concentrations of some PFAS," said co-author Jeff Burgess, a professor and the director of the Center for Firefighter Health Collaborative Research at the Zuckerman College of Public Health, per the University of Arizona. "Research into occupational exposure to PFAS is vital to reduce the health risks associated with PFAS, including but not limited to increases in rates of certain cancers, increases in cholesterol levels, lower antibody response to certain immunizations, and increased rates of certain adverse reproductive outcomes." Identifying the issue is the first step in addressing it. "To date, PFAS exposure in health care settings has not been widely studied, and the potential sources of exposure remain unclear," said Ellingson. "Therefore, it's important to further examine specific exposure routes and health consequences for firefighters and health care workers." Scientists are also working on ways to destroy PFAS. Do you worry about having toxic forever chemicals in your home? Majorly Sometimes Not really I don't know enough about them Click your choice to see results and speak your mind. Join our free newsletter for weekly updates on the latest innovations improving our lives and shaping our future, and don't miss this cool list of easy ways to help yourself while helping the planet.
The Irish Sun
2 days ago
- Entertainment
- The Irish Sun
‘Breathtakingly beautiful' – Paige Spiranac leaves fans speechless as she puts on busty display in low cut green dress
PAIGE SPIRANAC stunned fans once again as she put on a classy display in a green dress. The golf influencer flashed a devilish smile for the camera in a snap she shared on social media. 26 Paige Spiranac stunned fans in a low-cut dress 26 The influencer often shares glam snaps on social media Credit: instagram @_paige.renee 26 Fans go wild for her outfits Credit: Instagram / _paige.renee 26 Piage shared her US Open tips last week Credit: X @PaigeSpiranac Paige, 32, left fans speechless after posing in a low-cut green dress. She shared a link to her exclusive site, which offers fans a behind the scenes glimpse into the former golfer's life. Fans loved Paige's look and showered her with compliments. One reacted saying: "One exceptionally beautiful woman." READ MORE ON PAIGE SPIRANAC Another added: "Breathtakingly beautiful." A third wrote: "Beautiful as always." And another commented: "Absolutely gorgeous!!!!!" Paige sent fans wild last week as she Most read in Golf She backed stars such as Meanwhile, Paige has recently announced that 'Beauty and brains...' - Paige Spiranac sends fans wild as she shares her US Open predictions in busty outfit The Grass League features both amateur and professional players in team-based formats. Paige boasts millions of online fans after embracing social media to promote her golf journey. The 32-year-old turned pro for a year after playing at the University of Arizona and San Diego State. A glimpse inside Paige Spiranac's glamorous life... 26 Paige Spiranac has defended her sexy outfits and says she feels comfortable in them Credit: Instagram 26 She gains messages of support whenever she posts a new photo Credit: Instagram @_paige.renee 26 Paige promoted her golfing equipment wearing this tiny, pink leotard Credit: Instagram 26 Paige dressed as Harley Quinn for Halloween in 2022 Credit: Instagram @_paige.renee 26 Paige dressed as Cammy from Street Fighter for last year's Halloween Credit: Instagram 26 Paige showed off her bum in bright red hot pants to celebrate March Madness Credit: Instagram 26 Paige has also shown her appreciation for baseball in the past Credit: Instagram 26 Paige celebrated the US Open in a stars and stripes bikini, eating hot dogs Credit: Instagram 26 In an homage to Top Gun, Paige dressed as a sexy fighter jet pilot Credit: Instagram 26 Paige has amassed a strong following across her various profiles Credit: Instagram/_paige.renee 26 Paige used to be a professional golfer but turned into a social media star Credit: Instagram @ 26 Paige shares a series of raunchy pics on a daily basis Credit: Instagram @_paige.renee 26 Paige also talks about golf across her popular pages Credit: Instagram / @_paige.renee 26 Paige is golf's top influencer Credit: Instagram @_paige.renee 26 She regularly delivers golf tips to fans Credit: Instagram @ 26 Paige loves posting saucy photos Credit: instagram @_paige.renee 26 She's a firm believer in her golf advice Credit: Instagram / _paige.renee 26 She has plenty of followers online Credit: instagram @_paige.renee 26 Paige is not shy of the camera Credit: INSTAGRAM @_paige.renee 26 Paige regularly thrills with saucy snaps Credit: Instagram @ 26 With followers often seeing her on the course Credit: Instagram @_paige.renee 26 She regularly shares revealing snaps Credit: Twitter / PaigeSpiranac
The Irish Sun
12-06-2025
- Entertainment
- The Irish Sun
‘Beauty and brains…' – Paige Spiranac sends fans wild as she shares her US Open predictions in busty outfit
PAIGE SPIRANAC has given her US Open tips - but fans were too busy going wild for her busty outfit. The influencer and former LPGA star believes golf stars are in for a difficult time at the tournament. Advertisement 20 Paige Spiranac, Credit: X @PaigeSpiranac 20 Paige Spiranac, Credit: X @PaigeSpiranac The Paige shared her tips for the competition on her Instagram story. She has backed stars such as However, she also backed a couple of lesser-known stars to impress. Advertisement READ MORE ON GOLF "Oakmont is well bunkered with firm, fast greens with thick rough, thicker than a bowl of oatmeal. "This is going to be a true test from start to finish, every single shot. "No surprise the favourites will be Scottie Scheffler and Bryson DeChambeau. Advertisement Most read in Golf "For some dark horses, I am looking at Harris English and Ben Griffin. "I am looking for carnage this week and fingers crossed, we get an over-par winner." 'I'm pumped for you' - Fans love Paige Spiranac's shock new career move into 'big, high-powered executive job' 20 She has backed Scottie Scheffler to impress at the US Open Credit: instagram @_paige.renee 20 She sharted the tips with her followers on social media Credit: Instagram @_paige.renee Advertisement However, fans were far too distracted by her busty outfit, which was a floral white dress. Fans flocked to social media to hail the look. One posted: "Beauty and brains. A rare combination." A second wrote: "You are beautiful." Advertisement A distracted third commented: "What she say?" A fourth said: "She makes a boring sport appear sexy." Another added: "Beautiful dress." Meanwhile, Paige has recently announced that Advertisement The Grass League features both amateur and professional players in team-based formats. Paige boasts millions of online fans after embracing social media to promote her golf journey. The 32-year-old turned pro for a year after playing at the University of Arizona and San Diego State. But her LPGA career failed to take off, with Spiranac swapping the fairway for the online world. Advertisement She has built up a loyal following thanks to a hearty mix of golf tips and A glimpse inside Paige Spiranac's glamorous life... 20 Paige Spiranac has defended her sexy outfits and says she feels comfortable in them Credit: Instagram 20 She gains messages of support whenever she posts a new photo Credit: Instagram @_paige.renee 20 Paige promoted her golfing equipment wearing this tiny, pink leotard Credit: Instagram Advertisement 20 Paige dressed as Harley Quinn for Halloween in 2022 Credit: Instagram @_paige.renee 20 Paige showed off her bum in bright red hot pants to celebrate March Madness Credit: Instagram 20 Paige has also shown her appreciation for baseball in the past Credit: Instagram 20 Paige celebrated a previous US Open in a stars and stripes bikini, eating hot dogs Credit: Instagram Advertisement 20 In an homage to Top Gun, Paige dressed as a sexy fighter jet pilot Credit: Instagram 20 Paige has amassed a strong following across her various profiles Credit: Instagram/_paige.renee 20 Paige used to be a professional golfer but turned into a social media star Credit: Instagram @ 20 Paige shares a series of raunchy pics on a daily basis Credit: Instagram @_paige.renee Advertisement 20 Paige also talks about golf on her popular social media pages Credit: Instagram / @_paige.renee 20 She's a firm believer in her golf advice Credit: Instagram / _paige.renee 20 She has plenty of followers online Credit: instagram @_paige.renee 20 With followers often seeing her on the course Credit: Instagram @_paige.renee Advertisement 20 She regularly shares revealing snaps Credit: Twitter / PaigeSpiranac
