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The death of an animal companion can be every bit as devastating as other types of loss.On “The Daily Show” this week, the host Jon Stewart broke down as he announced the death of his beloved, three-legged brindle pit bull, Dipper — a raw, touching segment that exemplified the deep grief many pet owners feel.When an animal dies, owners lose companionship, affection and “just plain unconditional love — and we don’t find that in many places in our lives,” said Sherry Cormier, a psychologist and author of “Sweet Sorrow: Finding Enduring Wholeness After Loss and Grief.”Our society tends to be “grief-phobic,” Dr. Cormier said, and there is a sense that the feelings prompted by the loss of a pet are relatively low in the hierarchy of suffering, or that it’s something that people should be able to cope with and move on from quickly. Dr. Cormier and other loss experts said that is not always true; and they shared ways to help a loved one through the loss of a pet.Validate the owner’s loss.Pet loss can lead to disenfranchised grief, meaning it is not validated or acknowledged by the wider world, said Michelle Crossley, an associate professor at Rhode Island College and vice president of the Association for Pet Loss and Bereavement. Therefore, “a lot of individuals end up grieving in isolation because of fear of rejection from other people,” she said, adding, “They worry that they won’t understand or they’ll minimize the loss.”Keep it simple when expressing your sympathies, Dr. Cormier said. She suggested something like: “I know your animal was such an important part of your life and family. I can see how much he meant to you and how much you’re already missing him.”Pet grief is often complicated by feelings of guilt if your friend or loved one opted to put an animal down to minimize suffering, Dr. Cormier said. She has done so with two golden retrievers, but noted the circumstances were quite different. One lived a long, happy life; the other had to be put down unexpectedly because of an aggressive brain tumor.We are having trouble retrieving the article content.Please enable JavaScript in your browser settings.Thank you for your patience while we verify access. If you are in Reader mode please exit and log into your Times account, or subscribe for all of The Times.Thank you for your patience while we verify access.Already a subscriber? Log in.Want all of The Times? Subscribe.

A complaint said the official, who oversees diversity, equity and inclusion efforts at Columbia’s medical school, also copied work from at least 28 other authors.An official in charge of diversity, equity and inclusion at Columbia University’s Irving Medical Center was accused this week of plagiarizing large sections of his doctoral dissertation, according to an anonymous complaint filed with the university.The 55-page complaint accused the official, Alade McKen, of copying material in his 2021 dissertation at Iowa State University from more than two dozen other scholars and from Wikipedia, which is written and edited by volunteers from the general public.The complaint was published online Thursday by The Washington Free Beacon, a conservative news website that led a campaign last year against the former president of Harvard University, Claudine Gay. She resigned in January following accusations of plagiarism and after her response to antisemitism on campus was criticized.Plagiarism allegations have rocked the world of elite academia in recent months. They have often had explicitly political overtones, with conservative critics leveling accusations against left-leaning administrators and at least one high-profile accusation that has been portrayed as an act of liberal revenge.The complaint published online on Thursday accused Mr. McKen of copying passages of his dissertation from the Wikipedia entry for “Afrocentric education” and from the published scholarship or the doctoral dissertations of at least 28 people.“Is Alade McKen a plagiarist?” the anonymous author of the complaint wrote at the top of page 1. “A small selection of examples from his dissertation are included below to guide your investigation.”We are having trouble retrieving the article content.Please enable JavaScript in your browser settings.Thank you for your patience while we verify access. If you are in Reader mode please exit and log into your Times account, or subscribe for all of The Times.Thank you for your patience while we verify access.Already a subscriber? Log in.Want all of The Times? Subscribe.

Published3 hours agoShareclose panelShare pageCopy linkAbout sharingImage source, Getty ImagesBy Smitha MundasadHealth reporter More than a billion people are living with obesity around the world, global estimates published in The Lancet show.This includes about 880 million adults and 159 million children, according to 2022 data.The highest rates are in Tonga and American Samoa for women and American Samoa and Nauru for men, with some 70-80% of adults living with obesity.Out of some 190 countries, the UK ranks 55th highest for men and 87th for women. The international team of scientists say there is an urgent need for major changes in how obesity is tackled.Obesity can increase the risk of developing many serious health conditions, including heart disease, type 2 diabetes and some cancers.Ranking global obesity rates (the percentage of population classed as obese, after age differences are accounted for), researchers found:The US comes 10th highest for men and 36th highest for womenIndia ranks 19th lowest for women and 21st lowest for menChina is 11th lowest for women and 52nd lowest for menSenior researcher Prof Majid Ezzati, of Imperial College London, told the BBC: “In many of these island nations it comes down to the availability of healthy food versus unhealthy food.”In some cases there have been aggressive marketing campaigns promoting unhealthy foods, while the cost and availability of healthier food can be more problematic.”Prof Ezzati, who has been looking at global data for years, says he is surprised at the speed the picture has changed, with many more countries now facing an obesity crisis, while the number of places where people being underweight is regarded as the biggest concern, has decreased. Half of world could be overweight by 2035Obesity ‘linked to cancer rise’The report, spanning 1990 and 2022, found the rate of obesity quadrupled among children and adolescents. Meanwhile for adults, the rate more than doubled in women and nearly tripled in men.At the same time, the proportion of adults classed as underweight has fallen by 50%, but researchers emphasise it still remains a pressing problem, particularly among the poorest communities.World Health Organization (WHO) director general Dr Tedros Adhanom Ghebreyesus said: “This new study highlights the importance of preventing and managing obesity from early life to adulthood, through diet, physical activity, and adequate care.”He added that it would take the work of governments and communities and “importantly requires the co-operation of the private sector, which must be accountable for the health impacts of their products”.Study co-author Dr Guha Pradeepa, from the Madras Diabetes Research Foundation, says major global issues risk worsening malnutrition caused by both obesity and being underweight.She said: “The impact of issues such as climate change, disruptions caused by the Covid-19 pandemic and the war in Ukraine risk worsening both rates of obesity and underweight, by increasing poverty and the cost of nutrient-rich foods.”The knock-on effects of this are insufficient food in some countries and households, and shifts to less healthy food in others.”The network of more than 1,500 researchers, collaborating with the WHO, analysed height and weight measurements from some 220 million people aged five and over.They used a measure called body mass index.While they acknowledge this is an imperfect measure of the extent of body fat, and say some countries had better data than others, they argue it is the most widely used, making this global analysis possible.More on this storyHalf of world could be overweight by 2035Published3 March 2023Obesity ‘linked to cancer rise’Published7 January 2016Related Internet LinksThe LancetThe BBC is not responsible for the content of external sites.

Magnetite, a tiny particle found in air pollution, can induce signs and symptoms of Alzheimer’s disease, new research suggests.
Alzheimer’s disease, a type of dementia, leads to memory loss, cognitive decline, and a marked reduction in quality of life. It impacts millions globally and is a leading cause of death in older individuals.
The study, Neurodegenerative effects of air pollutant particles: Biological mechanisms implicated for early-onset Alzheimer’s disease, led by Associate Professor Cindy Gunawan and Associate Professor Kristine McGrath from the University of Technology Sydney (UTS) was recently published in Environment International.
The research team, from UTS, UNSW Sydney and the Agency for Science, Technology and Research in Singapore, examined the impact of air pollution on brain health in mice, as well as in human neuronal cells in the lab.
Their aim was to better understand how exposure to toxic air pollution particles could lead to Alzheimer’s disease.
“Fewer than 1% of Alzheimer’s cases are inherited, so it is likely that the environment and lifestyle play a key role in the development of the disease,” said Associate Professor Gunawan, from the Australian Institute for Microbiology and Infection (AIMI).
“Previous studies have indicated that people who live in areas with high levels of air pollution are at greater risk of developing Alzheimer’s disease. Magnetite, a magnetic iron oxide compound, has also been found in greater amounts in the brains of people with Alzheimer’s disease.

“However, this is the first study to look at whether the presence of magnetite particles in the brain can indeed lead to signs of Alzheimer’s,” she said.
The researchers exposed healthy mice and those genetically predisposed to Alzheimer’s to very fine particles of iron, magnetite, and diesel hydrocarbons over four months. They found that magnetite induced the most consistent Alzheimer’s disease pathologies.
This included the loss of neuronal cells in the hippocampus, an area of the brain crucial for memory, and in the somatosensory cortex, an area that processes sensations from the body. Increased formation of amyloid plaque was seen in mice already predisposed to Alzheimer’s.
The researchers also observed behavioural changes in the mice that were consistent with Alzheimer’s disease including increased stress and anxiety and short-term memory impairment, the latter particularly in the genetically predisposed mice.
“Magnetite is a quite common air pollutant. It comes from high-temperature combustion processes like vehicle exhaust, wood fires and coal-fired power stations as well as from brake pad friction and engine wear,” said Associate Professor McGrath from the UTS School of Life Sciences.
“When we inhale air pollutant, these particles of magnetite can enter the brain via the lining of the nasal passage, and from the olfactory bulb, a small structure on the bottom of the brain responsible for processing smells, bypassing the blood-brain barrier,” she said.

The researchers found that magnetite induced an immune response in the mice and in the human neuronal cells in the lab. It triggered inflammation and oxidative stress, which in turn led to cell damage. Inflammation and oxidative stress are significant factors known to contribute to dementia.
“The magnetite-induced neurodegeneration is also independent of the disease state, with signs of Alzheimer’s seen in the brains of healthy mice,” said Dr Charlotte Fleming, a co-first author from the UTS School of Life Sciences.
The results will be of interest to health practitioners and policymakers. It suggests that people should take steps to reduce their exposure to air pollution as much as possible, and consider methods to improve air quality and reduce the risk of neurodegenerative disease.
The study has implications for air pollution guidelines. Magnetite particles should be included in the recommended safety threshold for air quality index, and increased measures to reduce vehicle and coal-fired power station emissions are also needed.

A new study from a team of McGill University and Vanderbilt University researchers is shedding light on our understanding of the molecular origins of some forms of autism and intellectual disability.
For the first time, researchers were able to successfully capture atomic resolution images of the fast-moving ionotropic glutamate receptor (iGluR) as it transports calcium. iGluRs and their ability to transport calcium are vitally important for many brain functions such as vision or other information coming from sensory organs. Calcium also brings about changes in the signalling capacity of iGluRs and nerve connections which are a key cellular events that lead to our ability to learn new skills and form memories.
iGluRs are also key players in brain development and their dysfunction through genetic mutations has been shown to give rise to some forms of autism and intellectual disability. However, basic questions about how iGluRs trigger biochemical changes in the brain’s physiology by transporting calcium have remained poorly understood.
In the study, the researchers took millions of snapshots of the iGluR protein in the act of transporting calcium, and unexpectedly discovered a temporary pocket that traps calcium on the outside of the protein. With this information at hand, they then used high-resolution electrophysiological recordings to watch the protein in motion as it transported calcium into the nerve cell.
“The results are important because we describe for the first time the mechanism by which calcium is transported, which ultimately drives the cellular processes that lead to learning and memory,” said Derek Bowie, McGill’s lead author of the study, published in Nature Structural and Molecular Biology and co-Director of the Cell Information Systems group in the School of Biomedical Sciences.
The biological mechanism discovered is not only conserved amongst all species of mammals, but is also found in organisms that branched away from the evolutionary pathway of humans more than 500 million years ago.
“The original blueprint of the protein design was so good it seems that evolution did not need to change it,” said Bowie.
“Visualizing the tiny ions and water molecules in the channel pore using cryo-EM technology was quite an amazing experience. It highlighted an ancient calcium binding pocket which we were able to understand further from a functional perspective in collaboration with Bowie Lab. Our finding is fundamental to calcium signaling in neurons and raises interesting hypotheses about synaptic function that could be tested by experiments in the future,” said Nakagawa, Vanderbilt’s lead author and Professor at the Department of Molecular Physiology and Biophysics at the School of Medicine Basic Sciences.
About the study
The open gate of the AMPA receptor forms a Ca2+ binding site critical in regulating ion transport by Teru Nakagawa, Xin-tong Wang, Federico Miguez-Cabello and Derek Bowie, was published in Nature Structural & Molecular Biology.

A technique originally devised to extract DNA from woolly mammoths and other ancient archaeological specimens can be used to potentially identify badly burned human remains, according to a new study from Binghamton University, State University of New York.
Fire victims may be identified through dental records if the teeth are preserved and such records exist. Oftentimes, DNA testing is the only way to identify badly burned bodies. Researchers can extract usable DNA from bones subjected to conditions between 200 and 250 degrees centigrade; between 350 and 550 degrees, there is a steep drop-off in the concentration of DNA.
“In effect, there’s an inverse correlation: the higher the burn temperature, the less DNA is preserved,” explained Binghamton University Research Assistant Professor of Anthropology Matthew Emery, the lead author. “Part of the idea was to look at how DNA degrades systematically across different temperature ranges.”
The researchers used two different techniques to extract DNA from the bones and teeth of 27 fire victims from incidents that included house fires, airplane crashes, truck fires and motor vehicle accidents.
One technique was originally devised to extract ancient DNA from Ice Age megafauna and is also used on human remains found in archaeological contexts, such as Neanderthals. The second, known as the total demineralization protocol, was devised by Odile Loreille, a forensic scientist with the FBI and one of the paper’s co-authors.
Both were adequate at obtaining data up to the 350-degree mark. Below that temperature, the forensic DNA protocol may be preferable, while the ancient DNA technique allows for the amplification of shorter DNA fragments, which makes it useful in hotter fires.
The researchers also devised a method to determine the heat of fires by looking at the bone discoloration patterns. Bones subject to temperatures below 200 degrees Celsius are typically well-preserved, while yellow and brown discoloration indicates temperatures between 200 and 300 degrees, and a black or smoked appearance range between 300 and 350 degrees. Bones subject to temperatures between 550 and 600 degrees may appear gray, with temperatures above that leading to a white or calcined appearance.

With this knowledge, forensic scientists can select which bones may be the most appropriate for DNA extraction.
“The whole point of the study is to devise a best practices approach for forensic anthropologists and forensic scientists working in the field,” Emery said.
In addition to fire temperature, the type of bone also matters. Long bones — tibia, femur, ulna, and those in your hands and feet — tend to be the best reservoirs because they are thick with a hard exterior that tends to preserve DNA, he explained.
Emery is currently working on another project with the Maricopa County burn remains, looking to identify cold-case victims.
“In these cases, the technology wasn’t there at the time to identify them,” he said. “The same techniques that are used in the field to get DNA from woolly mammoths, we’re now using to get DNA from victims in cold cases.”
“Targeted Enrichment of Whole-Genome SNPs (single nucleotide polymorphism) from Highly Burned Skeletal Remains” was recently published in the Journal of Forensic Sciences.
Co-authors include Binghamton University Assistant Professor of Anthropology Laure Spake; Anne Stone, Emery’s mentor at Arizona State University, where he did a postdoctoral fellowship; Katelyn Bolhofner, Jane Buikstra, Suhail Ghafoor, Cyril Versoza, Erin Rawls, and Stevie Winingear from Arizona State; Laura Fulginiti, a forensic anthropologist with the Maricopa County Medical Examiner’s Office in Arizona; and by Odile Loreille, a forensic scientist with the FBI laboratory.

Bile acids long have been known to play a role in human metabolism. Synthesized from cholesterol in the liver, bile acids are involved in digestive processes, particularly in absorbing fat. They also are modified extensively by bacteria, which greatly expand the types of bile acids found in the host.
For most of a century, scientists believed that was the end of the bile-acid story. Recent technological advances, however, have led to a greater understanding of the origins of bile acids as well as their chemical relationships to the organisms in the gut microbiome and their host. Deploying some of these technologies, a team led by Penn State researchers has uncovered the mechanism by which bacteria generate a wide variety of new bile acid species, the functions of which are not yet clear.
The researchers, who published their results recently in Nature, identified a new role for an old bacterial enzyme, known as bile salt hydrolase, or BSH. The enzyme modifies human- and mouse-generated bile acids and changes their configurations by, for example, adding amino acids, leading to new molecules known as bacteria bile acid amidates, or BBAAs.
The team also showed, for the first time, that these BBAAs are made in humans at birth, coinciding with the establishment of the gut microbiome in newborns.
“The influence of bile acids on health and disease is well established,” said corresponding author Andrew Patterson, professor of molecular toxicology and the John T. and Paige S. Smith Professor in Penn State’s College of Agricultural Sciences. “But now we’re finding that they can serve as signaling molecules between us and our microbial counterparts. It’s like a communication network between us and microbes, with bile acids being the messenger.”
Patterson, who also holds an appointment as professor of biochemistry and molecular biology in the Eberly College of Science, explained that the hundreds — and perhaps thousands — of new bile acid species created by BSH-producing bacteria may have far-reaching signaling properties.
“Researchers have reported finding bile acids in the brain, skin and other tissues,” he said. “This suggests that they probably have a broader role beyond just helping us consume fat. Discovering what this role could be is a question we’re still trying to answer, and that’s what’s really exciting about this research.”
Although the researchers are unsure about the long-term implications of their study, they pointed out that BSH and bile acids have been linked with many health conditions, such as inflammatory bowel disease, some cancers and obesity. Understanding their role eventually could lead to therapies, they said.

“There are many diseases associated with abnormal lipid or bile acid metabolism — if you can’t absorb fat properly, you’re going to have problems,” Patterson said. “Teasing out the functions of these new bile acid species opens a lot of new doors to explore.”
To test their hypothesis that bile salt hydrolase is involved in the creation of bile acids, the researchers took a multipronged approach. In some experiments, they used an inhibitor to block the bacterial activity of BSH, and in others, they modified bacteria to remove the gene that encodes for BSH. In the absence of BSH, there was no production of BBAAs, the team found.
Working with the Children’s Hospital of Philadelphia and the University of Pennsylvania, the researchers also tested stool samples of infants from birth to 12 months old. They found that a rise in bile acids, including BBAAs, coincided with the colonization of BSH-producing bacteria in the infants’ guts. It is the first time scientists have connected BBAA production with BSH-expressing bacteria during human infant development, according to the researchers.
The results of this study reinforce, and are reinforced by, a parallel study that was conducted at Michigan State University and published in the same issue of Nature. Although the research teams did not work together directly — and approached the topic from different angles — they shared information and collaborated to publish their studies simultaneously, Patterson explained.
“Publishing these papers at the same time was a great example of land-grant collaboration,” he said. “Having two independent labs come up with the same answer really bolsters the significance of the findings, which in some ways upend 100 years of thinking in the field.”
Robert Quinn, whose lab published the MSU study, noted that his team showed that the BSH enzyme produced bile acids, while the Patterson lab did the reverse, identifying the enzyme and inhibiting it, which revealed that these molecules went away.

“It was perfectly complementary,” said Quinn, assistant professor in MSU’s Department of Biochemistry and Molecular Biology.
Bipin Rimal, co-first author of the Penn State paper, echoed the sentiment.
“These highly interdisciplinary collaborations at Penn State, Michigan State and places across the country helped transform a simple idea into something that reshapes our understanding of the role of BSH,” said Rimal, who received his doctorate in 2023 while working in Patterson’s lab.
Patterson credited talented graduate students, a diverse interdisciplinary team cooperating across campus and coast-to-coast, and the availability of technologies such as mass spectrometry and nuclear magnetic resonance platforms for making his lab’s discoveries possible.
Penn State study co-first author Stephanie Collins, a doctoral alumna of the Patterson Lab, agreed. “Without the technological capabilities and having the right mix of people here at the right time, we could not have accomplished what we did,” she said.
Also part of the research team from Penn State were Megan Granda, Fuhua Hao and John Vanden Heuvel, Department of Veterinary and Biomedical Sciences; Nushrat Hoque, Department of Chemistry; Imhoi Koo, Huck Institutes of the Life Sciences; Erin Reilly, Min Soo Kim, Jordan E. Bisanz and Emily Weinert, Department of Biochemistry and Molecular Biology; Devendra Paudel and Vishal Singh, Department of Nutritional Sciences; and Dhimant Desai and Shantu Amin, Department of Pharmacology.
Other researchers on the paper represented Children’s Hospital of Philadelphia, East Carolina University, the University of Michigan, the University of California San Diego, the National Cancer Institute and the University of Pennsylvania.
The National Institutes of Health, the Rosalind E. Franklin Science Achievement Graduate Fellowship program in Penn State’s Eberly College of Science, the Huck Institutes of the Life Sciences at Penn State, the American Beverage Foundation for a Healthy America, the Crohn’s and Colitis Foundation, the American Heart Association postdoctoral fellowship program, the Pennsylvania Department of Health, the U.S. Department of Agriculture’s National Institute of Food and Agriculture, and Penn State supported this work.

Every year, millions of older Americans spend money and time to try to look younger than they are. They color graying hair, buy anti-balding products, use teeth whiteners and wrinkle fillers, and much more.
Now, a new study looks at what this kind of effort means for older adults’ experiences with the ageism that pervades American society. The study also explores how a person’s perception of how old they look relates to both their positive and negative age-related experiences, and their physical and mental health.
In all, 59% of adults age 50 to 80 say they think they look younger than other people their age. The percentage was slightly higher among women and among people with higher incomes, more years of education and current employment.
On the other end of the spectrum, only 6% of older adults said they look older than other people their age. The rest said they look about the same as their peers. A slightly higher percentage of those who were ages 50 to 64 said they look older than their peers, compared with those ages 65 to 80.
As for trying to look younger, the study finds that about one-third of older Americans (35%) have invested time or money toward this goal. Those more likely to say they’d done so included women, those with higher incomes and people of Hispanic origin.
The study, based on data from a national survey conducted for the University of Michigan National Poll on Healthy Aging, is published in the journal Psychology and Aging by a team from the University of Oklahoma, Norman and Michigan Medicine, U-M’s academic medical center.
In addition to asking about appearances, the poll asked older adults about both positive and negative experiences related to aging and ageism. Positive ones included being asked for advice and wisdom, and feeling a strong sense of purpose, while negative ones included having others assume they have difficulty seeing, hearing, remembering or using technology.

Those who feel they look younger than other people their age were more likely to score higher on the scale of positive age-related experiences, and lower on the scale of negative ageism experiences.
Those who said they had invested time or money in looking younger were more likely to score higher on the positive scale too; this was especially true for those who are married or have a partner.
However, the news for those who had tried to look younger wasn’t all rosy. Those who said they had invested in strategies to look younger were also more likely to score higher on the scale of negative experiences related to aging. This relationship was especially strong for non-Hispanic Black and White respondents but not for Hispanic respondents.
Meanwhile, those who say they look older than others their age were much more likely to score higher on the negative ageism experiences scale, and lower on the positive age-related experiences scale.
The study also looks at how someone’s self-reported health status related to their experiences around aging.
Overall, those who had more positive and fewer negative experiences related to aging were also more likely to say they’re in good or very good health, both physical and mental.

The higher someone’s score on the positive experiences scale, the more likely they were to also say they were in good mental and/or physical health. But the higher someone’s score on the negative ageism experiences scale, the more likely they were to also say that they are in fair or poor physical and/or mental health.
“Taken together, these findings suggest a complex and nuanced relationship between how older adults feel about their age-related appearance and the experiences they have, both positive and negative, related to their age,” said first author Julie Ober Allen, Ph.D., M.P.H., of the Department of Health and Exercise Science, University of Oklahoma, Norman.
Allen worked on the survey during her time as a postdoctoral fellow at the Population Studies Center at U-M’s Institute for Social Research. She adds, “Feelings and experiences of ageism, which are rooted in our society’s emphasis on youthfulness and bias against aging, appear to indirectly have a relationship with health, both mental and physical.”
The researchers note that the difference between the percentage who feel they look young for their age, and the percentage who said they had spent money or time to look younger, itself may reflect both the pervasive bias against aging, and the specific bias against admitting that one has done something to change appearances, especially among men.
The findings suggest that while clinicians and public health authorities should be cautious about reinforcing beliefs that signs of aging are undesirable, they can help adults understand ways that health choices with implications for age-related aspects of appearance may also reduce their likelihood of experiencing both age-related discrimination and poor health outcomes later in life, adds poll director and co-author Jeffrey Kullgren, M.D., M.S., M.P.H., a primary care provider at the VA Ann Arbor Healthcare System and U-M internal medicine associate professor.
“We know that healthier eating, more physical activity, better sleep, stress reduction techniques, preventive oral hygiene, use of sunscreen, and reducing or eliminating use of tobacco, alcohol and other substances can all impact appearance later in life, as well as physical and mental health,” he said. “And many of these interventions are less costly, or at least more evidence-based, than the many commercial products and services that claim to reduce signs of aging.”
The team previously published a report on some of the poll data. The data formed the basis for two scales used in the new study — one based on how adults responded to statements about positive experiences related to aging, and one on 10 negative statements about their age-related experiences and perceptions. This latter scale has been published as a standardized Everyday Ageism Scale that any researcher can use.
In addition to Allen and Kullgren, the study’s authors are Valerie Moïse, M.S., Marshall K. Cheney, Ph.D. and Daniel Larson, PhD of the University of Oklahoma, Norman, and Erica Solway, Ph.D., Preeti N. Malani, M.D. and Dianne Singer, M.P.H. of U-M and IHPI.
The poll data come from a national survey of more than 2,000 people between ages of 50 and 80 conducted in 2019. The National Poll on Healthy Aging is based at the U-M Institute for Healthcare Policy and Innovation and supported by AARP and Michigan Medicine.
How Old Do I Look? Aging Appearance and Experiences of Aging Among U.S. Adults Ages 50-80, Psychology and Aging, https://doi.org/10.1037/pag0000800

In a landmark study, researchers at University of Washington and The Jackson Laboratory have characterized, in exacting detail, the rapid series of events that transform a single fertilized cell into a living, complex being. The work, reported this month in Nature, not only has enabled the team to explore which genes drive the differentiation of hundreds of cell types, but also shows, for the first time, that there are very rapid changes in genetic activity within the hour immediately following birth, underscoring the speed with which newborns must adapt.
“The scale of the single cell data set is massive,” says JAX Research Scientist Ian Welsh, Ph.D., who, along with JAX Associate Professor Stephen Murray, Ph.D., possesses key expertise in embryo morphogenesis, the generation of embryonic structures such as limbs and organs. Together they designed the strategy to collect and precisely organize the samples by developmental stage.
In mice, the whole process from one cell to more than 500 million takes less than three weeks. A team, led by Jay Shendure, Ph.D., of theUniversity of Washington, characterized the process in exacting detail, profiling nuclei in 12.4 million cells from 83 embryos that span prenatal development from embryonic day eight to birth. In each of these nuclei, Shendure and his team sequenced messenger RNA to identify cells by which genes are being expressed and how active they are, ultimately constructing a tree of cell-type relationships from fertilized egg to birth.
Mouse embryonic development has typically been studied in 24-hour increments after an egg is fertilized. An ambitious goal of this study was to increase the resolution of the analysis by staging embryos at two- to six- hour intervals. However, complicating the task is that gestational time is not strictly correlated with developmental stage, in that different embryos reach developmental milestones at different times, even within the same litter.
“Our contribution to the project is the rigor of sample collection and, importantly, exact staging of the samples with respect to each other in ‘absolute’ developmental time,” says Welsh. “Imagine trying to reconstruct a feature length film by gluing together a pile of each of the individual frames. The more accurately that you can place those frames in time, the more accurately you will reconstruct the movie.”
Over the course of development, the formation of new cell types mostly occurred gradually, with cells well mixed across adjacent time points. A surprising exception was the transition from late-stage fetus to newborn. Certain cell types — kidney, brown fat, and others — showed very rapid changes in genetic activity within the hour immediately following birth. The findings underscore the magnitude of the change from placental to extrauterine life.
As a foundation, the findings point the way to future studies. For example, better understanding of the post-birth adaptive functions — and the mechanisms underlying their rapid use — may help explain the differences in long-term physiology and health outcomes between human babies born via C-section versus vaginal delivery. And extending the framework could, in theory, yield a single-cell-time-lapse of the entire mammalian lifespan, from conception to death.

Leafy green vegetables are important sources of dietary fiber and nutrients, but they can harbor harmful pathogens. In particular, lettuce has often been involved in outbreaks of foodborne illness across the U.S. A new study from the University of Illinois Urbana-Champaign examines factors that affect E. coli contamination on five different leafy greens — romaine lettuce, green-leaf lettuce, spinach, kale, and collards.
“We are seeing a lot of outbreaks on lettuce, but not so much on kale and other brassica vegetables. We wanted to learn more about the susceptibility of different leafy greens,” said lead author Mengyi Dong, now a postdoctoral research associate at Duke University. Dong conducted the research as a doctoral student in the Department of Food Science and Human Nutrition (FSHN), part of the College of Agricultural, Consumer and Environmental Sciences (ACES) at the U. of I.
The researchers infected whole leaves from each of the five vegetables with E. coli O157:H7 and observed what happened after storage at 4° C (39° F), 20° C (68° F), and 37° C (98.6° F). Overall, they found that susceptibility was determined by a combination of temperature and leaf surface properties such as roughness and the natural wax coating.
“At room temperature or higher, E. coli grows very fast on lettuce, but if lettuce is refrigerated at 4° C (39° F), we see a sharp decline in the E. coli population. However, for waxy greens like kale and collard, we get the opposite results. On these vegetables, E. coli grows slower under warmer temperatures, but if it is already present, it can survive longer under refrigeration.”
Even so, kale and collard are overall less susceptible to E. coli contamination than lettuce. Furthermore, these vegetables are usually cooked — which kills or inactivates E. coli — while lettuce is consumed raw. Rinsing lettuce does help, Dong said, but doesn’t remove all the bacteria because of their tight attachment to the leaf.
The researchers also inoculated cut leaves with E. coli O157:H7 to compare the intact surface of a whole leaf to the damaged surface of a cut leaf.
“Whole leaves and freshly cut leaves present different situations. When the leaf is cut, it releases vegetable juice, which contains nutrients that stimulate bacterial growth,” Dong explained. However, the researchers found that spinach, kale, and collard juice actually exhibited antimicrobial properties that protect against E. coli.
To further explore these findings, they isolated juice (lysate) from kale and collards and applied the liquid to lettuce leaves, finding that it can be used as a natural antimicrobial agent. The potential applications could include antimicrobial spray or coating to control foodborne pathogen contaminations at both pre-harvest and post-harvest stages, the researchers said.

“We can’t completely avoid pathogens in food. Vegetables are grown in soil, not in a sterile environment, and they will be exposed to bacteria,” said co-author Pratik Banerjee, associate professor in FSHN and Illinois Extension specialist.
“It’s a complex problem to solve, but we can embrace best practices in the food industry and food supply chain. There’s a lot of interest from the research community and federal agencies to address these issues, and the USDA imposes high standards for food production, so overall the U.S. food supply is quite safe.”
Banerjee and Dong emphasize they do not want to discourage people from eating fresh fruit and vegetables; they are part of a healthy diet. Just follow food safety guidelines, wash your lettuce thoroughly, store it in the refrigerator, and pay attention to any food safety recalls in your area, they conclude.
This project was supported by the USDA Specialty Crop Block Grant Program (SCBGP) through the Illinois Department of Agriculture [grant numbers IDOA SC-22-20].