Electric vehicles cost more to buy than gasoline cars, and they may lose value more quickly. Even for people eager to own a car with no tailpipe emissions, it’s reasonable to wonder whether it makes sense to buy one now.The answer may well be yes, but there are a lot of factors to consider, many of which depend on your driving habits and how important it is to you to reduce your impact on the environment. And because electric vehicles are a new technology, there is less certainty than for gasoline-powered vehicles about how the numbers will shake out over time.Here’s what we know.Is battery longevity a problem?Most electric cars haven’t been on the road that long, so it’s hard to say definitively how long batteries will remain usable. Lithium-ion batteries, the kind used in virtually all electric vehicles, do lose range over time.But the degradation is very slow. Electric cars from Tesla and other automakers have software that does a good job of protecting batteries from excess heat or voltage that can cause damage, especially when charging.Federal regulations require automakers to guarantee electric vehicle batteries for eight years or 100,000 miles, though manufacturers interpret that rule in different ways. Most will replace a battery if it loses more than 30 percent of its capacity during the warranty period.One thing to note: Batteries will still work in freezing weather and extreme heat, but their range could be temporarily reduced.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.

In a new report, the American Academy of Pediatrics said that breastfeeding problems were rarely caused by infant tongue-ties.In recent years, more and more women struggling to breastfeed have taken their babies to a dentist to sever the tissue under the tongue.But little evidence supports the use of these “tongue-tie releases” for most babies, according to a report published on Monday by the American Academy of Pediatrics, which represents 67,000 doctors. The tongue procedures, which often cost several hundred dollars, should be done only to the small fraction of infants with severely tethered tongues, the report said.“Our patients are paying out-of-pocket, outrageous amounts for something they don’t need,” said Dr. Jennifer Thomas, a pediatrician in Wisconsin who oversees the academy’s breastfeeding group and was the lead author of the report.Dr. Thomas said she and her colleagues began working on the report nearly nine years ago when they noticed a significant uptick in parents asking them to check their infants for tongue-ties. One study estimated an 800 percent rise in the number of tongue-tie procedures between 1997 and 2012.A New York Times investigation last year found that some dentists and lactation consultants aggressively promoted the surgery, despite a risk of side effects. Serious complications are rare. But doctors told The Times that they had seen the cuts cause such pain that babies had refused to eat, becoming dehydrated and malnourished. A few said that newly floppy tongues blocked infants’ airways.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.

FamilyThe mother of a young boy with complex needs has called for all special schools to have CCTV after her son was attacked by a teaching assistant.

It was much more accurate than primary care doctors using cognitive tests and CT scans. The findings could speed the quest for an affordable and accessible way to diagnose patients with memory problems.Scientists have made another major stride toward the long-sought goal of diagnosing Alzheimer’s disease with a simple blood test. On Sunday, a team of researchers reported that a blood test was significantly more accurate than doctors’ interpretation of cognitive tests and CT scans in signaling the condition.The study, published Sunday in the journal JAMA, found that about 90 percent of the time the blood test correctly identified whether patients with memory problems had Alzheimer’s. Dementia specialists using standard methods that did not include expensive PET scans or invasive spinal taps were accurate 73 percent of the time, while primary care doctors using those methods got it right only 61 percent of the time.“Not too long ago measuring pathology in the brain of a living human was considered just impossible,” said Dr. Jason Karlawish, a co-director of the Penn Memory Center at the University of Pennsylvania who was not involved in the research. “This study adds to the revolution that has occurred in our ability to measure what’s going on in the brain of living humans.”The results, presented Sunday at the Alzheimer’s Association International Conference in Philadelphia, are the latest milestone in the search for affordable and accessible ways to diagnose Alzheimer’s, a disease that afflicts nearly seven million Americans and over 32 million people worldwide. Medical experts say the findings bring the field closer to a day when people might receive routine blood tests for cognitive impairment as part of primary care checkups, similar to the way they receive cholesterol tests.“Now, we screen people with mammograms and PSA or prostate exams and other things to look for very early signs of cancer,” said Dr. Adam Boxer, a neurologist at the University of California, San Francisco, who was not involved in the study. “And I think we’re going to be doing the same thing for Alzheimer’s disease and hopefully other forms of neurodegeneration.”In recent years, several blood tests have been developed for Alzheimer’s. They are currently used mostly to screen participants in clinical trials and by some specialists like Dr. Boxer to help pinpoint if a patient’s dementia is caused by Alzheimer’s or another condition.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.

BBCThey are the

Chloe DaviesA woman whose body does not recognise when to stop swelling says a drug trial has been “life-changing”.

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Blood testing partnership Synnovis has warned that its hacked blood transfusion services may not be fully functioning again until the autumn.

Getty ImagesThe European Medicines Agency (EMA) has

In the era when people traveled by sailing ship and steamer, illnesses usually burned themselves out before boats reached shore, a new study finds.On Dec. 22, 1874, the H.M.S. Dido arrived in Fiji from Sydney, Australia, carrying about 200 people and an invisible payload. A king of Fiji and his son, who were on the ship, were infected with measles. When they debarked, they started an epidemic that killed 20,000 people in Fiji — up to one-fourth of the population — who had no immunity to the disease.But in those days, when people traveled by sail or steam, such events were the exception rather than the rule. A new report, published last week in The Proceedings of the National Academy of Sciences, uses mathematical models to show how viruses had to beat very long odds to be transmitted across the sea. Most often, the study found, infectious diseases burned themselves out on board before ships ever docked.In the contemporary world, it is expected that new diseases and older infectious menaces will spread almost instantly around the globe, as happened with Covid-19. But where was the inflection point? Elizabeth Blackmore, a doctoral student at Yale, and James O. Lloyd-Smith, an ecologist at the University of California, Los Angeles, set out to find the moment when viral transmission started to change.John McNeill, a historian at Georgetown University who was not involved in the study, said Ms. Blackburn’s use of sophisticated mathematical modeling “has achieved something here that no historian or anybody else has been able to do before — to quantify likelihoods of transmission.”Kyle Harper, a historian at the University of Oklahoma who was also not involved in the study, said the work “breaks new ground.”Ms. Blackmore said that she and Dr. Lloyd-Smith thought of the idea to look at shipping when she was working on her master’s degree. They learned that the first reports of smallpox outbreaks of smallpox in California were not until 1806 and 1838. And smallpox was first reported much later elsewhere in the Pacific.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.