Tag Archives: compared

Evolutionary Factors Behind Women’s Longer Lifespans Compared to Men’s

Posted on by
Reply
SEI 268503325

Women live longer than men in all countries on average

Peter Cabana/Aramie

The most extensive assessment of lifespan disparities between male and female mammals and birds has provided new insights
into why women generally outlive men.

The average global life expectancy for women is around 74 years, compared to 68 years for men. Various theories propose reasons for this difference, such as the tendency of younger men to suffer higher rates of accidents or conflicts, and the protection women have against dangerous mutations in sex chromosomes. However, the explanations remain incomplete.

In a search for answers from other species,
Johanna Stärk from the Max Planck Institute for Evolutionary Anthropology and her team examined data on average life expectancy across 1,176 species (528 mammals and 648 birds) observed in both zoos and in the wild.

They discovered that in 72% of mammal species, females live longer than males by an average of 12 to 13%. Conversely, in birds, males tend to outlive females in 68% of species, surviving approximately 5% longer.

Researchers posit that this trend supports the hypothesis that sex chromosomes may account for some lifespan differences.

In mammals, the presence of two X chromosomes in females grants individual genetic protection, unlike males who possess an X and a Y chromosome. This may provide women with a better safeguard against harmful mutations.

For birds, the sex determination system is reversed; females have one Z and one W chromosome while males carry two Z chromosomes. This discrepancy suggests that the gender on different chromosomes may incur different longevity costs.

“What’s particularly intriguing is when we identify exceptions,” says team member
Fernando Colcello,
also at the Max Planck Institute. “These exceptions prompt further testing of evolutionary theories regarding gender differences in lifespan.”

Diving deeper into the data, the researchers found that mating systems might influence these outcomes. In polygamous mammals, where competition is prevalent among males, those individuals usually have shorter lifespans than females.

“In the race for mating opportunities, males often invest in characteristics favored in sexual selections, such as size or ornate features,” explains
Nicole Riddle from the University of Alabama.
“These traits are costly to develop, and competition can lead to additional expenditures on aggressive behaviors.”

Such factors can result in reduced resources available for personal survival, she states.

Men who invest in expensive traits to acquire mates may have shorter lifespans

Rebius/Shutterstock

This phenomenon is also seen in polygamous birds. “Overall, this may explain the comparatively lower male dominance in bird species,” states
Pau Carazo from the University of Valencia in Spain.

He explains that in mammals, both genetic factors and sexual selection influence shorter male lifespans, while in birds, strong sexual selection pressures on males and the varied costs for females may counterbalance the effects.

Stärk and her colleagues additionally found that those who invest more in offspring care tend to live longer, which is predominantly the case for females in mammals. In long-lived species such as humans and primates, this trait may confer an evolutionary advantage by ensuring that mothers survive until their offspring reach sexual maturity.

However, exceptions exist. “In predatory species, the opposite pattern emerges,” notes Stärk. “Females are typically larger and often take on roles in territory defense, yet they still exhibit longer lifespans,” leaving this phenomenon an ongoing enigma.

Carazo remarks that gender lifespan differences can lead to smaller populations in zoos compared to the wild. This controlled environment may also be a factor in the reduced lifespan discrepancies observed among human genders, though these differences are unlikely to vanish completely.

“Significant physiological and genetic differences between men and women remain,” explains Colcello. “The future trajectory of medical science is uncertain, but we generally do not anticipate these differences to fully eliminate.”

topic:

Source: www.newscientist.com

Baby’s Brain Development May Affect Their Slow Adaptation to Mites Compared to Adults

Posted on by
Reply

The infant’s brain functions at a distinct rhythm compared to that of adults

Goodles/Aramie

When infants attempt to comprehend their surroundings, their brain activity reveals slower rhythms compared to adults, aiding them in grasping new concepts.

Our brains utilize a network of neurons to interpret sensory input. When a neuron receives a sufficiently strong signal from its neighbor, it transmits that signal to other neurons, generating synchronized waves of electrical activity that alternate between activated and silent states.

These brain waves manifest at various frequencies. A specific brain area may show a greater proportion of neurons synchronized to one frequency over others if it exhibits a range of frequencies simultaneously. For instance, prior research indicates that the adult visual cortex displays a diverse range of frequencies when individuals are observing stimuli, but in higher proportions, more neurons synchronize with the waves at a frequency of 10 hertz.

To determine if the same holds true for infants, Moritz Kester from the University of Regensburg in Germany along with his colleagues enlisted 42 eight-month-olds via their parents. The researchers recorded the infants’ brain activity with electrodes affixed to the scalp, exposing them to dozens of friendly cartoon monsters for about 15 minutes, each monster flashing for two seconds.

The team relied on the fact that brain waves tend to oscillate in sync with rapidly flickering images, enabling them to assess the number of neurons synchronized to various frequencies within the infants’ visual cortex. Each monster was toggled on and off at eight different frequencies ranging from 2 to 30 hertz.

Analysis of the brain activity data revealed that the visual cortex produces waves of synchronized activity in response to the flickering cartoons. However, the most prominent signals emerged at four hertz, indicating greater synchronization with this flicker frequency than with others.

Moreover, this 4-hertz signal was consistently present even when the brain was exposed to flickering at higher frequencies, such as 15 hertz. “What’s particularly intriguing is that regardless of the different frequencies presented, a response at 4 hertz was always observed,” comments Kester.

This rhythm falls within a frequency band known as theta, which is associated with the formation of new concepts, potentially facilitating learning for young children as they observe their environment. “It suggests that infants are in a specific learning mode,” Kester explains.

Researchers supporting this theory further discovered that there were no 4-hertz EEG signals in the visual cortex, nor EEG signals at other frequencies, suggesting a broader neural circuit involvement in other brain areas related to concept formation.

Repeating the experiment with seven adults confirmed prior findings that visual brain circuits are predominantly activated by the 10 hertz frequency, which was also found to persist in the background despite varying speeds of the cartoon flickering.

Given adults’ extensive experiences, it appears that the visual sections of their brains are fine-tuned to respond to more frequent stimuli. They block irrelevant information and concentrate on acquiring conceptual knowledge, states Kester.

Further research is necessary to establish whether exposure to 4 hertz flickering images can enhance infants’ capacity to learn new concepts, according to Emily Jones at Birkbeck, University of London. The team is hopeful to gain further insights in an ongoing study, Kester added.

topic:

Source: www.newscientist.com

One Antiviral Shot Offers Superior Protection Compared to Influenza Vaccines

Posted on by
Reply

Influenza virus particles observed through an electron microscope, color enhanced

John G/Imago/Alamy

A promising long-term antiviral medication may offer protection against all strains of influenza, providing hope for the most vulnerable populations.

The flu results in the loss of thousands of lives annually, and the swift emergence of new variants poses a risk for future pandemics. Each year, scientists reformulate flu vaccines to correspond with the strains that are projected to be prevalent in the upcoming season. These vaccines prompt the immune system to generate antibodies that block the virus from infiltrating the cells.

Efforts are underway to develop a universal influenza vaccine capable of safeguarding individuals from all strains, yet these vaccines face challenges.

“Even if the first approved universal influenza vaccine is created, individuals exhibit varying immune responses, meaning not everyone will be effectively protected,” says Jeffrey Stein, CEO of Cidara. For instance, vaccines often show reduced efficacy in older adults or in those with compromised immune systems.

To tackle this issue, Stein and his team have developed a treatment known as CD388, which includes Zanamivir, an antiviral drug authorized for treating infections caused by all influenza variants that affect humans. Normally, Zanamivir is eliminated from the body within hours, but the research team has modified it to rapidly neutralize the invasive influenza virus. “It’s not part of the immune system,” Stein explains.

For testing, the team enrolled 5,000 participants aged 16-64 from the US and the UK at the beginning of the 2024 flu season. None of the participants were at elevated risk for flu-related complications or had received that year’s flu vaccine. They divided the participants into four approximately equal groups. Three groups received one injection of CD388 at low, moderate, or high doses, while the final group received a placebo.

About six months later, researchers assessed the number of individuals with symptomatic flu infections during the flu season, defined by the presence of influenza virus DNA in nasal swabs and flu-like symptoms such as cough and fever.

Thirty-three individuals in the placebo group reported symptomatic flu, whereas only eight participants in the high-dose CD388 group did, marking a risk reduction of around 76%. The moderate and low-dose groups saw a 61% and 58% decrease in risk of symptomatic infections, respectively. “All doses demonstrated significant protection against influenza illness,” states Nicole Dhabapana, Chief Medical Officer of Sidara. Side effects, such as injection site tenderness, were consistent across both the treatment and placebo groups.

The results indicate that CD388 may offer a more straightforward means of protecting individuals compared to vaccines. “[Unlike vaccines, it] does not need to match the circulating strain, and could be more effective during a ‘poor match’ year or for pandemic preparedness, especially if new flu strains, such as H5N1, transmit to humans,” remarks Pennyword from King’s College London. She adds that, based on previous data on Zanamivir, it is unlikely that influenza strains will develop resistance to it.

This approach is likely to be effective for older individuals and those known to have poor vaccination responses, including the immunocompromised. Davalpana mentions that the team plans to conduct tests on individuals aged 12 and older with compromised immune systems.

Instead of replacing vaccines, Stein suggests that the drug may work best in conjunction with them, although this has yet to be tested. Nevertheless, the findings are timely given the growing hesitance surrounding vaccinations. “We aim to bypass the controversy that unfortunately surrounds vaccines,” Stein remarks.

Topic:

Source: www.newscientist.com

Dementia Cases Surge More Rapidly in China Compared to Global Trends

Posted on by
Reply
A new scientist. Science News and Long read from expert journalists, covering developments in science, technology, health, and the environment.

Why are dementia cases sharply rising in China?

Hanohishikilf/Aramie

The incidence of dementia is escalating in China at an unprecedented rate, with numbers exceeding four times the historical figures observed over past decades.

Daoying Geng from The University of Hudun conducted an analysis of dementia statistics across 204 countries and regions between 1990 and 2021. The focus was on dementia cases in individuals over 40, particularly other forms like Alzheimer’s and cerebrovascular dementia.

During this timeframe, researchers discovered that global dementia cases surged from nearly 22 million in 1990 to approximately 57 million by 2021. The situation was particularly alarming in China, which saw its case count increase over fourfold to reach about 4 million.

In-depth analysis indicates that population growth plays a pivotal role. China experienced a baby boom in the 1950s, which means those individuals are now in their 70s, the age group presenting the highest risk for dementia. Xi Chen from Yale University, who did not participate in the study, noted the uniqueness of China’s baby boom generation compared to other countries’ cohorts.

The research team identified three additional significant contributors to the escalating dementia rates in China. First, smoking predominantly impacts men, with only 2% of Chinese women being smokers about half of the male population smokes. This contrasts sharply with countries like the US and UK, where smoking rates are on a downward trend, according to Chen.

A Western trend mirrored in China involves rising rates of diabetes and obesity, particularly over recent decades, both recognized risk factors for dementia. This shift may be attributed to the adoption of a Western-style diet, which is generally higher in fat and calories, Chen explains. He posits that as younger generations in China smoke less, dementia rates may eventually mirror those of the US or UK, albeit the present conditions continue to exert a substantial influence on China.

“Dementia is among the costliest diseases globally, necessitating extensive care and treatment,” Chen emphasizes. “As for aging, China possesses the largest elderly population worldwide. There are few young individuals to care for this significant number of seniors living with dementia, presenting numerous challenges.”

topic:

Source: www.newscientist.com

The potential reasons behind teenage girls’ higher rates of depression compared to boys

Posted on by
Reply

Researchers have discovered that certain chemical imbalances in the brain may help explain the higher risk of depression in teenage girls compared to boys.

They specifically highlighted the role of a chemical called tryptophan, an essential amino acid found in foods like turkey, chicken, eggs, milk, nuts, and seeds. Tryptophan is used by the body to produce serotonin, a brain chemical that influences mood, sleep, and happiness.

When tryptophan is broken down in the brain, it can lead to the production of beneficial chemicals like kynurenic acid, as well as harmful chemicals.

Tryptophan (the molecular structure shown here) is one of the 20 standard amino acids – Photo credit: Getty

A study by scientists from King’s College London analyzed blood and depression symptoms in Brazilian teenagers aged 14-16, linking these chemicals with depression in both genders.

According to Professor Valeria Mondeli, senior author and Kings’ clinical professor of psychoimmune, adolescence is a time of significant changes with little understanding of the biological factors contributing to depression differences between teenage boys and girls.

The researchers found that girls at high risk of depression had lower levels of brain health kynurenic acid compared to low-risk individuals, indicating potential harm from tryptophan breakdown.

Girls and women are twice as likely to experience depression compared to men, and the researchers suggested this may be linked to the unbalanced kynurenine pathway’s effects on the brain.

Dr. Nagum Nickhesrat, the first author of the study, expressed hope that the findings could lead to better support for teenagers with depression, possibly through drugs targeting the kynurenine pathway.

Understanding the kynurenine pathway’s role in depression development during teenage years could provide insight into better management strategies for depression.

Read more:

Source: www.sciencefocus.com

Hunters and gatherers tend to have shorter sleep durations compared to industrialized individuals.

Posted on by
Reply

Members of the Namibian HIMBA community get an average of 5.5 hours of sleep at night

Nick Fox/Aramie

Unlike our ancestors who lived in technologically advanced times, there is much written about how modern lifestyles mean that we no longer get enough sleep. However, an analysis of 54 sleep studies conducted around the world has shown that people in small, non-industrial societies actually sleep less than people in industrialized communities.

“Everyone I talk about in Canada and the US are talking about how bad their sleep is.” Leela Mackinnon At Toronto Mississauga University, Canada. “The numbers don’t show that.”

It is often assumed that the rise of gadgets like big screen televisions and smartphones means that people today are less sleepy than in the recent past.

However, many studies reporting sleep declines over the past few decades are based on asking people how long they spend sleep. This is an unreliable measure. Even using this method, The results are mixedmany studies have found that there is no change or even an increase in sleep duration.

Studies based on more reliable measurements, such as using physical activity monitors and electrodes to monitor brain waves, have not declined over the last few decades. For example, we found a 2016 review of 168 studies. There is no decline Sleep period for the past 50 years.

However, these studies have been conducted in developed countries and reveal the question of whether people had more sleep before industrialisation. Wrist-based activity monitors are now available, making it easier to study sleep in a non-industrial society.

Such studies have revealed an incredible short period of sleep. For example, among hunter-gatherers, Sun sleeps on average 6.7 hours per night, Hatza sleeps 6.2 hours, and Bayaka sleeps 5.9 hours per night. The shortest time ever found is 5.5 hours of sleep in the HIMBA community in Namibia, a herdsman of nomadic livestock.

McKinnon and her colleagues David SamsonUniversity of Toronto, University of Mississauga, is also involved in several such research. They now compare sleep habits in industrialized societies, including the US, Australia and Sri Lanka, with people from small, non-industrial communities, including the Amazon, Madagascar and the Pacific indigenous people.

Overall, the analysis is based on 54 studies that include direct measures of sleep in people over 18 years of age without serious health conditions. In total, only 866 people are involved in these studies, but the dataset is the most comprehensive to date, says Samson. “It’s the best now.”

Overall, these individuals slept on average 6.8 hours, while in non-industrial societies the average was 6.4 hours, while in industrial societies it was 7.1 hours.

The two also found that people from the industrial world were asleep for 74% of their time in bed.

McKinnon and Samson also evaluated the regularity of people’s circadian rhythms using a measure called the circadian function index, where the score of 1 is perfect. In non-industrialized communities, the average was 0.7 compared to 0.63 in industrial societies.

Samson attributes the higher period of sleep and increased sleep efficiency in industrialized societies to conditions that encourage sleep more. “We see that we have some real benefits from the safety and security of our sleep scene,” he says. “There’s no need to dodge the night or predators with rival human groups.”

Conversely, people in industrial areas are less exposed to clues that help to maintain a circadian rhythm, such as low night temperatures and bright daylight exposure. Although they did not appreciate this, both MacKinnon and Samson said that a low normal circadian rhythm would have a negative effect explaining why many people perceive their sleep as poor. I doubt there is a possibility of giving it.

What is not clear from the paper says that individuals in these 54 studies are representatives of the overall population. Nathaniel Marshall At Macquarie University in Sydney, Australia. “Special sampling is required to make a statement about epidemiological prevalence,” he says.

Samson said he looked into whether large sample sizes could change results, and concluded that there was no significant difference.

topic:

Source: www.newscientist.com

Electric vehicles are limited compared to gasoline and diesel vehicles

Posted on by
Reply

Charging station for electric cars in British Cornwall

Mat Cardie/Getty Image

Electric vehicles (EVs) are currently limited to gasoline and diesel. And the improved reliability is more than a fossil fuel -driven car every year because of the still technology.

Robert Elliott At the University of Birmingham, his colleagues analyzed nearly 300 million records from the forced British road. MotIt indicates the status, age, and mileage of all vehicles on the road between 2005 and 2022. This covers a total of about 29.8 million vehicles.

The results showed that the average life expectancy of EVS was 18, 4 years or more, it was 16 years, exceeding the average diesel vehicle in 8 years, and in 18. At present, the average EV covers 200,000 kilometers over a lifetime, exceeding 187,000 km, where the gasoline counter part clocked up, but has not reached 257,000 km, which reaches on average.

Elliott says that the result is not only a gasoline and diesel -run alternative, but also proves that it has already defeated them. The survey also shows that long -term reliability has improved. The possibility that the EV fails and reach Scrapheap in a specific year is about six times faster than the diesel, about twice the speed of gasoline vehicles.

“The early electric car was not so good and I couldn’t trust it,” Elliott says. “But I think the main point is that technology is very rapidly improved.”

“We are not an environmental crusade. I just want to give facts. Electric vehicles and batteries have been alive, have improved their skills, and have been improved again since this research,” he says. 。

MOT data does not contain information about the amount required for maintenance and repair cars between tests, but only overall life. Other research from the United States shows The maintenance cost of an electric vehicle is about $ 0.06 per mile, but for an internal combustion engine, the value is $ 0.10 per mile.

Rachel Aldred At Westminster University in the UK, it is said that if you leave the gasoline and diesel vehicles, you will be profitable to fight climate change and air pollution, but EVs emphasize that the EV is not a silver bullet.

“It’s still a very inefficient and limited solution,” ALDRED. “If most people are avoiding a private car, lack of physical activity, road injury, and [residual] The pollution is also the same -although it is obviously much better [than petrol or diesel vehicles]。 She says walking, or equivalent cycling and public transportation should be a priority for those who can use these modes.

topic:

  • transportation/ /
  • Electric car

Source: www.newscientist.com

Google’s AI asserts it can create superior chips compared to human designers, but experts are skeptical

Posted on by
Reply

Can AI design chips that are more efficient than those made by humans?

Yuichiro Kayano/Getty Images

Google DeepMind says its artificial intelligence is already helping design chips used in data centers and even smartphones. But some chip design experts are skeptical of the company’s claims that these AIs can plan new chip layouts better than humans.

He said the new method, dubbed AlphaChip, can design “superhuman chip layouts” in hours, rather than relying on weeks or months of human effort. anna goldie and Azaria Mirhoseiniaccording to researchers at Google DeepMind. blog post. This AI approach uses reinforcement learning to figure out relationships between chip components and receives rewards based on the quality of the final layout. However, independent researchers say the company has yet to prove that such AI can outperform expert human chip designers or commercial software tools, and they say they are unable to demonstrate that such AI can outperform expert human chip designers or commercial software tools, and that they believe that current state-of-the-art The company hopes to test AlphaChip’s performance on public benchmarks that include cutting-edge circuit designs.

“If Google provides experimental results for these designs, we’ll be able to make a fair comparison, and we hope everyone will accept the results,” he says. patrick madden At Binghamton University in New York. “Experiments take a day or two to run at most, and Google has nearly infinite resources. The fact that these results aren’t being provided speaks volumes to me.” He declined to comment.

Google DeepMind’s blog post says: update Google for 2021 nature A journal paper about the company’s AI process. Since then, Google DeepMind says AlphaChip has helped design three generations of Google’s Tensor Processing Units (TPUs). TPUs are specialized chips used to train and run generative AI models for services such as Google’s Gemini chatbot.

The company also claims that its AI-assisted chip designs outperform those designed by human experts and are steadily improving. AI accomplishes this by reducing the overall length of wire needed to connect chip components. This could reduce the chip’s power consumption and increase processing speed. Google DeepMind also said AlphaChip created the layout for a general-purpose chip used in Google’s data centers, while also helping MediaTek develop a chip used in Samsung’s phones.

However, the code published by Google lacks support for common industry chip data formats, which suggests the AI method is currently more suited to Google’s own chips, it said. . Igor Markovchip design researcher. “We have no idea what AlphaChip is today, what it does or doesn’t do,” he says. “We know that reinforcement learning requires two to three orders of magnitude more computational resources than techniques used in commercial tools, and typically lags behind. [in terms of] result. “

Markov and Madden criticized the original paper controversial Claim that AlphaChip outperforms anonymous human experts. “Comparisons to unnamed human designers are subjective, non-reproducible, and very easily fooled. Although it is possible that the human designer is not trying hard enough or is underqualified. , there are no scientific results here,” says Markov. “Imagine if AlphaGo were reported to have won against an unknown Go player.”

In 2023, independent experts who reviewed Google’s paper revoked his nature An explanatory article that initially praised Google’s efforts. The expert is andrew kern At the University of California, San Diego, Public benchmarking efforts When we tried to replicate Google’s AI methods, we found that they could not consistently outperform human experts or traditional computer algorithms. The best approach was commercial software for chip design from companies like Cadence and NVIDIA.

“Reinforcement learning appears to lag significantly behind the state-of-the-art in every benchmark that would be considered a fair comparison,” Madden says. “I don’t think that’s a promising research direction when it comes to circuit placement.”

topic:

Source: www.newscientist.com

The Positive Impact of Arts and Crafts on Happiness Compared to Employment

Posted on by
Reply

Creative hobbies give us a sense of self-expression and progress.

Botanical Vision/Alamy

Engaging in arts and crafts improves mental health and a sense that life is worth living, and these activities have positive effects that are equal to or greater than the improvements in mental health that come with employment.

Decades of research have shown that health, income, and employment status are key predictors of people’s life satisfaction. But researchers from Anglia Ruskin University in the UK wanted to explore what other activities and situations might improve mental health. “Crafts are accessible, affordable, and already popular, so we were interested in finding out whether they have health benefits,” the researchers say. Helen Keyes.

Keys and her colleagues analyzed more than 7,000 responses to the annual survey. Participate in the surveyThe survey asks people in England about their involvement in activities such as arts and culture, sport and internet use. All participants were also asked about their levels of happiness, anxiety, loneliness, life satisfaction and whether they feel their life is worth living.

More than a third of participants said they had done at least one arts or crafts activity in the past year, including pottery, painting, knitting, photography, filmmaking, woodworking, and jewelry making. The researchers found that engaging in arts and crafts was associated with higher scores across measures of mental health, even after accounting for factors such as health and employment status.

Although the increase was small (about 0.2 on a 10-point scale), crafting was a stronger predictor of feeling that life was worth living than factors that are harder to change, such as having a job.

“There’s something about making things that gives you a sense of progress and self-expression that you can’t get in a job,” Keys says. “You can take real pride in what you make, and you can see the progress in real time.” The positive effect of creative activities on people’s sense of value in life was 1.6 times higher than in a job situation.

Arts and crafts also increased happiness and life satisfaction, but did not produce significant changes in reported loneliness, which may be because many crafts can be done alone.

Promoting and supporting arts and crafts can be used as a preventative mental health strategy on a national scale, Keys said: “When people do it, they have fun. It’s an easy win.”

topic:

Source: www.newscientist.com

Newer, more fuel-efficient jets could actually worsen global warming compared to older aircraft

Posted on by
Reply

Contrails are clouds formed when water vapor condenses on the soot emitted by jet engines.

Markus Meinka/Alamy stock photo

Planes flying at higher altitudes create longer-lasting vapor trails that could cause more global warming. Because private jets and modern fuel-efficient jetliners fly at higher altitudes than other commercial airliners, these aircraft may be causing even more warming than previously thought.

The findings could help airlines decide which routes to fly to minimise contrails, he said. Edward Gryspeerdt “If we could predict the areas in the atmosphere where contrails will form accurately enough, we could fly planes around them to reduce this effect,” say researchers from Imperial College London.

In some conditions, soot particles emitted by jet engines can spew ice particles in the aircraft's wake, forming clouds called contrails, which contribute to the overall warming effect. It is estimated that half of the warming effect from aviation is due to contrails, rather than carbon dioxide emissions.

How long a contrail lasts determines how much warming it causes, but persistence is difficult to study. Gryspeerdt and his team combined flight data and satellite observations to match contrails to specific aircraft and examine how the type of aircraft is related to persistence.

Previously, studies had been done manually and only on a small scale. But using artificial intelligence, the team was able to analyze 64,000 flights. They found that private jets and other fuel-efficient jetliners, which typically cruise at altitudes of about 12 kilometers (38,000 feet), one kilometer higher than other planes, are more likely to produce longer-lasting contrails. “That was unexpected,” Grys-Pierto says.

Not all soot particles emitted by aircraft turn into ice particles, he said: The team thinks that as planes fly higher, a higher proportion of soot particles become ice seeds, but the overall size of the ice particles gets smaller.

Because the tiny ice particles fall slower, they fall into areas where the air is warmer, where it takes longer for the ice particles to sublimate back into water vapor, meaning the contrails linger longer and cause even more warming.

But the team can't say exactly how much warming contrails cause because the characteristics of high-altitude contrails are slightly different, so it's unclear whether the additional warming caused by contrails lasting longer exceeds the warming avoided by modern planes' lower fuel burn.

What's clear is that the impact of private jets has been underestimated: “The climate impact per passenger is much larger than we thought,” Griespeerdt says.

Because contrails are more visible over oceans and the researchers only had data from a single geostationary satellite, they only looked at flights over the western Atlantic around Bermuda.

Gryspeerdt said the findings may not apply to flights further north, such as over Greenland or Iceland, because the air at high altitudes is drier and contrails are less likely to form.

“This study highlights that high-altitude aircraft have a significant climate impact beyond carbon dioxide, mainly due to the persistent contrails they create,” said Christina Hentz of the European environmental group Transport and Environment.

High altitudes are primarily used for long-distance flights, which are excluded from European Union plans to reduce non-carbon-dioxide warming, and this shows the importance of switching to fuels that produce fewer soot particles, Hentz said.

topic:

Source: www.newscientist.com

Ancient fossils reveal slower growth rates in mammals compared to modern species from Jurassic period

Posted on by
Reply

Cruxatodon kiltlingtonensisA small mammal from the Jurassic period

Maiya Carrara

During the Middle Jurassic, small mammals lived much longer than modern ones and received parental care for years rather than weeks, suggesting that at some point there was a major change in the growth rates of small mammals, although the exact cause is unknown.

The discovery is based on two fossil skeletons of extinct mouse-sized creatures. Cruxatodon kiltlingtonensis, It lived on the Isle of Skye in Scotland about 166 million years ago, and its fossils were unearthed decades apart, the first in the 1970s and the second in 2016.

The unusual discovery of two fossils of the same species, one adult and one juvenile, allowed the team to compare the specimens to study how the animals grew and developed. “That meant we could ask questions we never dreamed of with just one specimen,” he says. Elsa Panciroli At the National Museum of Scotland.

First, the scientists used X-ray images to count the growth rings on the specimens' teeth, which are similar to growth rings on tree trunks and can be used to estimate age. They found that the adult specimens were about 7 years old, and the juvenile specimens were between 7 months and 2 years old.

Panciroli said he expected the fossil to be much younger, since the pup still had its baby teeth. “This was quite surprising, as this animal is about the size of a squirrel or a shrew,” Panciroli said. “We would have expected its teeth to grow back within a few weeks or months, so we could see straight away that it must have been developing quite differently. [than modern species].”

This discovery K. Quiltrington Mice took up to two years to wean from their mothers, a big jump from the few weeks most small mammals require today. Analysis of the length and size of the fossil bones reveals that the animals “grew throughout their lives,” Panchiroli says. Today, small mammals like mice grow rapidly when they're young but then stop growing as adults.

It's unclear exactly when and why small mammals evolved this way, but Panchiroli said it could be linked to environmental changes or it could be the result of mammals having warmer blood and a faster metabolism.

Panciroli and her team return to Skye every year, and are optimistic that they will be able to better understand these changes: “Hopefully in the coming years we'll find more fossils and new ways to ask these questions,” she says.

topic:

Source: www.newscientist.com

Women in India have been disproportionately impacted by COVID-19 compared to men in most countries.

Posted on by
Reply

In March 2020, a night-time curfew was imposed in New Delhi, India, as a preventive measure against COVID-19.

Yawar Nazir/Getty Images

The COVID-19 pandemic may have affected India more severely than previously estimated, with women, certain social groups and younger people experiencing the most severe declines in life expectancy.

Mortality estimates in India during the coronavirus pandemic have been based on official death records. But the lockdown disrupted this system, and already Under-reporting of women and children’s deaths Even before the pandemic, certain information such as caste and ethnicity was not collected. Sangeeta Vyas At Hunter College in New York

So Vyas and his colleagues collected information on mortality in India from the National Family Health Survey, a nation-wide survey that asks participants whether anyone in their household has died in the past four years and, if so, to provide data such as date of death, age, and sex (with only male and female options).

The researchers analyzed data from more than 765,000 participants who completed the survey in 2021. They found that deaths in 2020 were about 17% higher than in 2019. If a similar increase occurred across India, it would amount to about 1.2 million excess deaths in 2020. This is eight times the official number of COVID-19 deaths in India in 2020 and 1.5 times the World Health Organization estimate. QuoteAccording to research.

From 2019 to 2020, life expectancy across the entire sample fell by more than 2.5 years. 1.5 Years of Decline During the same period in the United States, changes in life expectancy also varied by sex, age, and social group.

For example, mortality rates fell by about three years for women and just over two years for men. This contrasts with global trends that show that men have experienced a larger increase in mortality than women during the COVID-19 pandemic. “These peculiar patterns in India are likely to be explained, at least in part, by gender inequality,” Vyas says.

preliminary survey In Indian households, women spend less on healthcare compared to men, and the pandemic may have exacerbated these existing disparities, it said. Riddhi Kashyap Oxford University researchers who co-authored the study say strict lockdowns could hinder access to obstetric care and increase obstetric mortality.

Unlike other countries, the decline in life expectancy observed in the study was mainly due to premature deaths: rising mortality rates among women and girls under 20 contributed about one year to the decline in life expectancy in 2020, roughly the same as the number of deaths among women aged 60 to 79.

“We believe the rise in mortality is stemming from indirect effects of the lockdown in India,” Vyas said, which could include disruptions to access to childhood vaccines and treatment for tuberculosis, a leading cause of death in the country.

There were also large differences between social groups: high-caste Hindus saw their life expectancy fall by 1.3 years, while Muslims and people belonging to lower castes saw their life expectancy fall by 5.4 and 2.7 years, respectively.

Public health experts have long been aware of health disparities in India, but the findings highlight the magnitude of those disparities, Vyas said. “Knowing how different populations are affected differently is important for crafting policy responses,” she said.

But the study had limitations. Due to disruptions during the lockdown, survey respondents came from only 14 of India’s 36 states and union territories, making the sample demographically representative of only about a quarter of India’s population. The study also didn’t look at causes of death. “We can only speculate as to why there are these patterns,” Kashyap says. “But we can’t say for sure what’s causing them.”

topic:

Source: www.newscientist.com

Research: Daily consumption of 100% orange juice reduces blood sugar levels compared to orange drink

Posted on by
Reply

A new study from Toronto Metropolitan University says 100% orange juice and sugar-sweetened beverages are not equivalent when it comes to their effects on food intake and blood sugar response, and should not be placed in the same category when making beverage decisions.

Consuming 100% orange juice before a meal reduces food intake at the next meal and lowers daily blood glucose concentrations in healthy, normal weight adults when compared to orange drink.

The World Health Organization suggests reducing free sugar intake to no more than 10% of daily energy intake to reduce the risk of unhealthy weight and tooth decay.

Consistent with these recommendations, some national dietary guidelines recommend reducing sugar intake from all sources.

However, these recommendations do not differentiate between sources of free sugars and are primarily based on data from observational studies, so the physiological mechanisms underlying the observed effects cannot be readily determined.

“Our findings highlight the importance of considering the source of sugar when considering overall health effects,” said Dr. Nick Bellissimo of Toronto Metropolitan University, senior author of the study. I am emphasizing that.”

The randomized, repeated measures study included 36 adult men and women with normal BMI levels who received 1 cup of 100% orange juice, orange flavored, 2 hours after a breakfast consisting of cereal, 2% milk, and 2% milk. Ingested sugar-sweetened beverages and water. Breakfast bar.

Blood sugar responses, average appetite, and subjective emotions were measured every 15 minutes for 60 minutes in 34 participants.

Glycemic responses and energy intake for the rest of the day were measured in 31 participants using continuous blood glucose monitors and food records.

Subjective sweetness and pleasantness were measured immediately after ingesting the test beverage.

Glycemic responses, average appetite, and subjective emotions were measured every 15 minutes for 60 minutes.

Food intake was measured 60 minutes after the pizza lunch.

Blood sugar levels were lower with 100% orange juice than with orange drink at 15, 30, and 45 minutes, but not after 60 minutes.

Blood sugar levels for the rest of the day were lower after drinking 100% orange juice compared to drinking orange or water.

The findings also showed that food intake at lunch and throughout the day was lower after consuming 100% orange juice compared to consuming orange drink.

Participants also had higher subjective comfort measures and enjoyed 100% orange juice more compared to orange beverages and water.

Using 100% orange juice instead of sugary drinks may reduce your total daily calorie intake and help regulate blood sugar levels.

100% orange juice contains flavonoids such as hesperidin, which can affect sugar absorption by slowing glucose transport, causing a delayed blood sugar response.

Consumption of 100% orange juice is associated with increased flavonoid intake, decreased added sugar, and higher quality diet.

The researchers said, “Consumption of 100% orange juice as a preload resulted in higher caloric compensation, lower total daily energy intake, and lower blood glucose concentrations compared to orange beverages.”

“Future longitudinal studies are needed to assess whether the habit of replacing sugar-sweetened beverages with 100% orange juice contributes to a healthier body weight and improved glycemic control.”

of paper It was published in the magazine nutrients.

_____

Stephanie Robayo other. 2024. Effects of her 100% orange juice and moderate sugar-sweetened beverages on subjective appetite, food intake, and glycemic responses in adults. nutrients 16 (2): 242; doi: 10.3390/nu16020242

Source: www.sci.news

The potential negative impacts on privacy of refusing cookies compared to accepting them

Posted on by
Reply

When you open a new website, do you choose to either accept or reject all cookies? New research suggests that choosing to reject cookies may actually reveal more information about yourself than if you simply “accept all cookies.”

In this digital age, cookies, which are pieces of data, are stored on our devices for various purposes such as remembering login information. However, cookies can also be used to track online behavior and tailor ads to individuals. This has led many people to refuse cookies in order to keep their personal information private and to prevent companies from using their data for marketing purposes.

Surprisingly, recent research presented at NeurIPS 2023 has shown that certain demographics are more likely to reject cookies, which could have implications for advertisers. Contrary to popular belief, rejecting cookies does not necessarily mean hiding one’s identity.

Results from the study showed that acceptance of cookies varies depending on the country and age of the individual. For example, individuals in the US over the age of 34 were more likely to refuse cookies, inadvertently sharing more of their data.

Advertisers could access five pieces of information from a person who accepts cookies, but only two pieces from a person who rejects them. In other words, declining cookies may not necessarily protect your identity. This demographic, which includes older adults, has been found to have less trust in tech companies and is more likely to reject cookies as a result.

It is important to note that the privacy laws in the United States are not as stringent as those in the EU, meaning that user data may not be as protected, especially for individuals who reject cookies.

Privacy is important to some people, but not to everyone

Researchers have found that older Americans are less likely to accept cookies, with only 28% of them choosing to do so. This compares to 40% of younger Americans who typically accept cookies. This indicates that the decision to reject cookies has a greater impact for younger Americans in protecting their identity.

The authors of the research are hopeful that their findings will help shape regulations for new technologies such as AI and inform policymakers. They emphasize that the decision to accept or reject cookies is not as simple as it may seem and may not always produce the intended effect.

So… does it make sense to refuse cookies?

Ultimately, the impact of privacy decisions is more complex than users may realize, and there are no definitive answers. Some recommendations include using more privacy-friendly browsers and supporting stronger privacy laws and regulations.

About our experts

Dr. Elizabeth Daly is a computer research scientist leading the Interactive AI Group at IBM Research in Dublin. She has published research in journals such as Frontiers of Artificial Intelligence and Artificial Intelligence Research Journal.

Dr. Eric Mealing is a researcher at IBM Research with publications in Advances in Neural Information Processing Systems, American Control Conference (ACC), and International Conference on Decision Making and Game Theory for Security.

Source: www.sciencefocus.com