(Press-News.org) BINGHAMTON, N.Y. -- A million years ago, dry seasons became more frequent and forests retreated before the encroaching savanna. Meanwhile, clustered around a nearby lake, our ancient ancestors fashioned stone tools.
During the long press of years, mud and sediment in that East African lake turned to stone, trapping pollen and microscopic organisms in its lattice. Today, researchers like Kennie Leet analyze samples of these ancient sediments, known as sediment cores, to create a picture of the environment early humans called home.
A doctoral student in geological sciences, Leet is the first author on "Labyrinth patterns in Magadi (Kenya) cherts: Evidence for early formation from siliceous gels," published in a recent issue of Geology, the leading journal in the field. Co-authors include Distinguished Professor of Geological Sciences and Environmental Studies Tim Lowenstein, her advisor, as well as Robin Renaut of Canada's University of Saskatchewan, R. Bernhart Owen of Hong Kong Baptist University and Andrew Cohen of the University of Arizona.
Leet's research is part of the National Science Foundation-funded Hominin Sites and Paleolakes Drilling Project (HSPDP), which looks at how the climate may have impacted hominin evolution in the East African rift. Overall, the project looks at the last 5 million years; Leet's portion of the project considers the last million.
She particularly focuses on the origin of the chert found in Kenya's Lake Magadi. A fine-grained rock that forms from siliceous material, chert is "cryptocrystalline," composed of crystals so small that they can't even be seen by high-powered microscopes, much less the naked eye.
Scientists believe that chert forms on the earth's surface and thus contains information about the environment at the time of its formation, she explained. Because of this quality, they can use chert to calculate the time period for particular climactic events, such as droughts -- not unusual in East Africa, where the climate oscillates between wet and dry periods.
Opening a window into the distant past, the chert points to an even larger trend.
"One of the surprising things we found was that there has been a progressive drying trend for the last million years in East Africa. It's just been progressively getting drier and drier," she said. "But in that, we still have the oscillation between wet and dry."
In the Geology article, she explores a labyrinth pattern she found in the rocks of this period. Patterns are common in nature, and this specific one is formed by drying, she explained.
"It tells us that all of the chert formation and solidification occurred near the surface, where there was exposure to air," she said. "Because this happened before the sediments were buried and compacted, there is other supporting evidence, such as really beautifully preserved plant fragments and single-celled organisms called diatoms."
The time period coincides with the region's transition from trees and forests to grasslands, which biologists and microbiologists on the team are able to track through pollen preserved in the sediment core. During that period, the early humans of Lake Magadi were also creating stone tools in new ways. Researchers wonder: Were these ancient communities moving about and trading more, prompted by drought?
Interestingly, the trend has reversed over the last decade, with the region becoming wetter. In fact, one of the places she stayed during a visit to Kenya in 2019 is now underwater, she said.
INFORMATION:
Researchers from University of Mannheim published a new paper in the Journal of Marketing that examines the effect of wage inequality on customer satisfaction and firm performance.
The study, forthcoming in the Journal of Marketing, is titled "Wage Inequality: Its Impact on Customer Satisfaction and Firm Performance" and is authored by Boas Bamberger, Christian Homburg, and Dominik M. Wielgos.
Irrespective of wage cuts and employee layoffs, the wages of top managers rose to record levels during the pandemic and wage inequality continues to grow worldwide. However, according to a 2015 OECD report, "wage inequality is harmful to long-term economic growth and undermines ...
The door has finally opened on screening newborn babies for pyridoxine-dependent epilepsy (PDE), a severe inherited metabolic disorder. This screening promises to enable better and earlier treatment of the disease. To identify new biomarkers that can be used in the newborn screening protocol, also known as the neonatal heel prick, researchers at the Radboud University Medical Center joined forces with scientists at the Radboud University's FELIX laser laboratory. They published their findings in The Journal of Clinical Investigation.
The discovery and identification ...
PULLMAN, Wash. - Even before the pandemic made Zoom ubiquitous, Washington State University researchers were using the video conferencing app to research a type of cannabis that is understudied: the kind people actually use.
For the study, published in Scientific Reports, researchers observed cannabis users over Zoom as they smoked high-potency cannabis flower or vaped concentrates they purchased themselves from cannabis dispensaries in Washington state, where recreational cannabis use is legal. They then gave the subjects a series of cognitive tests.
The researchers found no impact on the users' performance on decision-making tests in comparison to a sober control group but did find some memory impairments related to free ...
INDIANAPOLIS -- The vast majority of electronic health record (EHR) alerts attempting to reduce the prescribing of high-risk medications linked to dementia in older adults went unread in a study led by research scientists from Regenstrief Institute, Purdue University and Indiana University School of Medicine. The goal of the intervention was to facilitate the deprescribing of anticholinergics through both provider and patient-based alerts, however, engagement with the alerts was so low, the study team was unable to conclude if this approach could be ...
When blood flow to the brain is somehow reduced or restricted, a person can suffer what we know as a stroke (from "ischemic stroke" in medical jargon). Stroke is one of those conditions that seems fairly common. This isn't a misperception: just in Europe, there are over 1.5 million new cases each year.
Some strokes can be lethal, and when they're not they often result in serious damage to the victim's ability to move. In fact, stroke is one of the major causes of long-term disability today. Recovery can be a long and arduous road. Again, in Europe, under 15% of the patients ...
Software to help towns and cities use street-planting to reduce citizens' exposure to air pollution has been developed by researchers at the University of Birmingham.
Street planting, or 'green infrastructure', is an essential part of the urban realm, but there is a misconception that plants remove or 'soak up' a lot of pollution. Instead, planting at this scale primarily serves to redistribute pollution by changing air currents within streets and beside open roads.
Because of this, not only the position and amount of planting within a street, but also ...
Astronomers have designed and trained a computer program which can classify tens of thousands of galaxies in just a few seconds, a task that usually takes months to accomplish.
In research published today, astrophysicists from Australia have used machine learning to speed up a process that is often done manually by astronomers and citizen scientists around the world.
"Galaxies come in different shapes and sizes" said lead author Mitchell Cavanagh, a PhD candidate based at The University of Western Australia node of the International Centre for Radio Astronomy Research (ICRAR).
"Classifying the shapes of galaxies is an important step in understanding their formation and evolution, and can even shed light on the nature of the Universe itself."
Mr Cavanagh said that ...
Most common bone and joint (orthopaedic) procedures, such hip replacements and shoulder repair surgery, are not backed up by high quality evidence, mainly because of a lack of definitive trials, suggests an analysis of data published by The BMJ today.
Yet despite the lack of strong supporting evidence, some of these procedures are still recommended by national guidelines in certain situations, the findings show.
Musculoskeletal conditions affect around 1 in 4 UK adults and account for over 25% of all NHS surgical interventions at a cost of £4.76 billion each year.
National ...
Muscle relaxant drugs are largely ineffective for low back pain, despite being widely prescribed for this condition, suggests an analysis of the latest evidence published by The BMJ today.
The findings show that muscle relaxants might reduce pain in the short term, but the effect is too small to be considered clinically meaningful, and there is an increased risk of side effects.
But the researchers stress that the certainty of evidence is low and say large trials are urgently needed to resolve uncertainties around the use of these drugs for back pain.
Low back pain is a global public health problem and muscle relaxants (a broad class of drugs that include ...
Mandatory covid-19 vaccination for care home workers is unnecessary, disproportionate and misguided, warn experts
And is based on unreliable data
In The BMJ today, experts argue that mandatory vaccination is "unnecessary, disproportionate, and misguided."
The government decision to remove the right of care home staff in England to choose whether or not to be vaccinated against covid-19 is a profound departure from public health norms. The intended next step is a rapid and massive expansion of compulsory vaccination to legally require covid-19 and flu vaccination of all frontline health and social care workers, subject to consultation.
But Lydia Hayes, Professor of Law at Kent ...