I was ‘a handy patsy’ for police, says Andrew Malkinson as real rapist convicted
Paul Quinn was found guilty of a brutal rape in 2003 for which innocent Mr Malkinson was jailed for 17 years. Source link
All posts tagged: DNA
Natural selection is accelerating, massive DNA study finds
For years, the story of recent human evolution looked relatively quiet. Scientists studying ancient human DNA had found only a few dozen clear cases where natural selection appeared to strongly favor one version of a gene over another. As a result, it made it seem as though the most forceful kind of selection had played only a limited role after modern humans spread out of Africa. In addition, they formed distinct populations around the world. A new analysis upends that picture. Drawing on DNA from nearly 16,000 ancient people across West Eurasia, researchers found that directional selection, the kind that pushes certain genetic variants to rise or fall in frequency because they help or hurt survival and reproduction, has been far more common than once believed. Moreover, the team identified hundreds of such cases over the past 10,000 years. Selection appears to speed up after the rise of farming. The work, led by researchers at Harvard, was published in Nature. David Reich (left), Ali Akbari (right), and colleagues studied thousands of ancient genomes from West …
The DNA Fix for Aging
On his son’s fourth birthday, Michael Prescott had his first heart attack. Prescott, who worked as a civil engineer designing bridges in Tennessee, was in his 30s, and until that day, he had appeared to be in excellent health. But within two years of that first heart attack, he had four more. His doctors, who were baffled by his repeated medical crises, decided that he needed a heart transplant. In 2001, he underwent the procedure in Nashville. But a few years later, he needed a kidney transplant too. No one could explain why his organs were failing him. As time dragged on, Prescott’s symptoms became more outwardly visible. His skin began wrinkling like that of someone decades older than him, and he developed cataracts. By his early 40s, Prescott looked like he was in his 60s. When he attended baseball games with his son, Carter, people would mistake him for the boy’s grandfather. Frustrated, Prescott decided to diagnose himself. He would sit for hours in the living room in his favorite chair, his slim form …
How hidden soil fungi ‘steal’ bacterial DNA to control the rain
Tiny organisms on the ground – bacteria and fungi – have a “superpower” that allows them to reach up into the atmosphere and pull down the rain, according to a recent study. To understand how a microbe can control a storm, we first have to look at how clouds become rain. High up in the atmosphere, water doesn’t always freeze at 0°C. Temperatures are normally much lower at cloud level but pure water can stay liquid down to a bone-chilling -40°C. Most rain starts as ice. In the atmosphere, clouds are full of “supercooled” water – liquid that is colder than freezing but hasn’t turned to ice yet because it has nothing to hold onto. For a cloud to turn into rain or snow, it needs a “seed”– a tiny particle for water molecules to grab onto so they can crystallise into ice, then fall from the clouds as rain. Dust, soot and salt – swept into the clouds by wind – can do this, but they aren’t very good at it. They usually require …
Flipping a single DNA letter can trigger complete sex reversal
Humans have about 3 billion DNA bases in their genetic makeup. However, most of it does not encode for protein. In the last few decades, scientists have come to realize that while much of the non-coding portion of the genome was once thought to be irrelevant, there is now overwhelming evidence that this segment plays an important role in regulating when and how genes switch on and off. A new study conducted by Bar-Ilan University supports this finding. It reveals an example of how impactful a single change to this regulatory region can be, and how significantly one nucleotide alteration can affect an organism’s phenotype. In an article published in Nature Communications, researchers found that inserting one nucleotide into the regulatory region of a mouse’s genome caused XX mice that normally develop as females to develop as males with testes and male genitalia. This change occurred outside the protein-coding region. It was located roughly 500,000 bases away from the gene it regulates. “This is an extraordinary finding, particularly because just a minute alteration — a …
Best science books of all time: Why Watson’s The Double Helix is an infuriating book
James Watson’s The Double Helix was first published in 1968. How does it stand the test of time? There’s a strong case to be made that The Double Helix by James Watson is one of the greatest science books of all time– but I can’t recommend that anyone actually read it. Many parts of it are distasteful, especially in light of the odious old man that Watson became. “The Double Helix reinvented the scientific memoir. Watson rendered science not as a bloodless march from Fact to Fact, but as a passionate adventure whose direction depends on the individual personalities of scientists,” says Nathaniel Comfort at Johns Hopkins University, who is writing a biography of Watson. “That was really new, and it drew countless young people into science, men and women alike, which was a big part of his intent with the book.” The Double Helix is Watson’s account of how, between 1951 and 1953, he came to work on the structure of DNA with Francis Crick. The pair eventually cracked it with the help of …
New smart drugs precisely target and kill cancer cells
Cancer treatment has long been haunted by the same problem: how do you strike dangerous cells without hitting healthy ones nearby? A team at the University of Geneva has built a drug-delivery system meant to answer that question with unusual precision. Instead of relying on bulky antibodies alone, the researchers used synthetic DNA strands, small binding proteins called affibodies, and aptamers to create a kind of molecular checkpoint. The treatment activates only when the right combination of markers appears on a cell’s surface. That matters because many cancer drugs still damage healthy tissue along with tumors. Antibody-drug conjugates, or ADCs, have helped narrow that gap by linking a cancer-seeking antibody to a toxic payload. However, those therapies come with tradeoffs. Antibodies are large, which can make it harder for them to move deep into solid tumors. Most can carry only a limited number of drug molecules. The Geneva group took a different route. General design of DNA-drug conjugates (DDC) for computed delivery. (CREDIT: Nature Biotechnology) Their system uses DNA hairpins, engineered strands that remain inactive …
The Turin Shroud bears DNA from many people, plants and animals
The Turin Shroud bears an image of a man said to resemble Jesus Christ public domain/Art Collection 2/Alamy DNA analysis has identified a vast array of animal, plant and human material contaminating the Turin Shroud, complicating the story of the mysterious relic purported to be the cloth that Jesus Christ was wrapped in after his crucifixion 2000 years ago. The shroud, which measures 4.4 metres long and 1.1 metres wide, is one of the world’s most famous and controversial Christian artefacts. Its first documented location was in France in 1354, and for nearly half a millennium, it has remained at the Cathedral of Saint John the Baptist in Turin, Italy. In 1988, researchers used radiocarbon and accelerator mass spectrometry dating techniques to determine that the shroud was made sometime between 1260 and 1390, excluding the possibility that the person perceived as being imprinted on the cloth could have been Jesus. However, this dating of the shroud to the later medieval period remains contested by some scholars of Christianity. In 2015, Gianni Barcaccia at the University …
The Shroud of Turin bears DNA from many people, plants and animals
The Shroud of Turin bears an image of a man said to resemble Jesus Christ public domain/Art Collection 2/Alamy DNA analysis has identified a vast array of animal, plant and human material contaminating the Shroud of Turin, complicating the story of the mysterious relic purported to be the cloth that Jesus Christ was wrapped in after his crucifixion 2000 years ago. The shroud, which measures 4.4 metres long and 1.1 metres wide, is one of the world’s most famous and controversial Christian artefacts. Its first documented location was in France in 1354, and for nearly half a millennium, it has remained at the Cathedral of Saint John the Baptist in Turin, Italy. In 1988, researchers used radiocarbon and accelerator mass spectrometry dating techniques to determine that the shroud was made sometime between 1260 and 1390, excluding the possibility that the person perceived as being imprinted on the cloth could have been Jesus. However, this dating of the shroud to the later medieval period remains contested by some scholars of Christianity. In 2015, Gianni Barcaccia at …
Teen convicted of manslaughter after asthma inhaler DNA matched to crime scene cigarette butt | UK News
A 19-year-old has been convicted over a fatal stabbing after police matched DNA on a cigarette found at the scene to that on his asthma inhaler. Ali Abdul Basit was convicted at the Old Bailey on Friday for his role in killing Michael Patrick Afonso Peixoto, 27, Metropolitan Police said. Basit’s conviction followed a two-year investigation, after he fled to Pakistan. Mr Peixoto was attacked in Thornton Heath in south London on 19 December 2023, police said. A group of men in a white BMW were seen waiting in the road when Mr Peixoto arrived with a friend in a Vauxhall Grandland on the night of the killing. The 27-year-old father was stabbed multiple times with a knife after he stepped out of the car, including once in the chest as he attempted to climb back in. Image: Michael Patrick Afonso Peixoto. Pic: Metropolitan Police The victim’s friend was threatened with a knife and forced out of the car. The vehicle was later found abandoned nearby. Mr Peixoto was found by police officers on the …