Top stories: a disgraced surgeon, ancient human voyages, and an antibody-coated bacterium
Disgraced surgeon is still publishing on stem cell therapies
Paolo Macchiarini, an Italian surgeon, has been fired from two institutions and faces the retraction of many of his papers after findings of scientific misconduct and ethical lapses in his research. Yet this hasn’t prevented him from publishing again in a peer-reviewed journal. Macchiarini appears as senior author on a paper investigating the viability of artificial esophagi “seeded” with stem cells, work that appears strikingly similar to the plastic trachea transplants that ultimately left most of his patients dead. The journal’s editor says he was unaware of Macchiarini’s history before publishing the study.
Ancient humans settled the Philippines 700,000 years ago
In what some scientists are calling a “one-in-a-million find,” archaeologists have discovered a cache of butchered rhino bones and dozens of stone tools on the Philippines’s largest island, Luzon. The find pushes back the earliest evidence for human occupation of the Philippines by more than 600,000 years, and it has archaeologists wondering who exactly these ancient humans were—and how they crossed the deep seas that surrounded that island and others in Southeast Asia.
By wrapping itself in antibodies, this bacterium may become a stable, beneficial part of the gut
Antibodies are one of the body’s most effective defenses against microbial pathogens. But at least one of these immune system proteins helps an apparently harmless bacterium make itself a lasting home in the human gut. The bacterium seems to coax immunoglobulin A, one of the most abundant antibodies produced by mammals, to cover its surface, helping it stick to the mucus lining of the gut and become a stable part of the microbiome, the constellation of microbes inhabiting our gut. The finding, in germ-free mice, could one day help researchers trying to treat a variety of conditions by adding microbes to the human body.
AI researchers allege that machine learning is alchemy
Ali Rahimi, a researcher in artificial intelligence (AI) at Google in San Francisco, California, took a swipe at his field last December—and received a 40-second ovation for it. Rahimi charged that machine learning algorithms, in which computers learn through trial and error, have become a form of “alchemy,” unable to decipher why some algorithms work and others don’t. Now, in a paper presented on 30 April at the International Conference on Learning Representations in Vancouver, Canada, Rahimi and his collaborators document examples of what they see as the alchemy problem and offer prescriptions for bolstering AI’s rigor.
This ocean path will take you on the longest straight-line journey on Earth
If you want to go on the longest boat ride in the world, but you don’t have a rudder, what route would you take? Five years ago, a reddit user proposed that traveling overseas from southern Pakistan to northeastern Russia would yield a trip of 32,090.3 kilometers—the longest straight-line journey on Earth. Now, a team of scientists has finally proved him right.