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Scientists have been trying for decades to develop an effective vaccine against HIV (virus particles shown in blue).Credit: Steve Gschmeissner/Science Photo Library

An experimental HIV vaccine that promises the longest-lasting protection so far will start a late-stage clinical trial later this year. More than 100 HIV vaccines have been tested in people in the past three decades, but only one has demonstrated any kind of protection, which waned within a year. One of the biggest challenges is the huge diversity of HIV strains circulating in the world. The new vaccine contains a disabled common-cold virus that carries synthetic HIV genes and proteins based on lots of strains from around the globe.

Nature | 4 min read

The United Arab Emirates will become the first Arab nation to launch a planetary-science mission when it sends a space probe called Hope to Mars in July 2020. The mission’s goals include understanding why Mars is losing its atmosphere by tracking the escape of hydrogen and oxygen, and building a bigger picture of the changing Martian atmosphere.

Nature | 2 min read

Researchers at the University of Alaska are waiting anxiously to see how administrators will apply a US$130-million cut to the state’s contribution to the university system, authorized by the state’s governor, Mike Dunleavy. The university’s governing board has already voted to consolidate the system’s three main branches in Anchorage, Fairbanks and Juneau. The funding crisis has forced some researchers to pull out of projects and is threatening climate-research facilities, including the International Arctic Research Center in Fairbanks.

Nature | 5 min read

FEATURES & OPINION

As scientists from myriad fields rush to perform algorithmic analyses, computer scientist Patrick Riley shares three problems in machine-learning analyses that his team at Google has faced and overcome. Be sure to split data appropriately, look for hidden variables and keep your eyes on the overall objective, says Riley.

Nature | 9 min read

Is the placenta sterile or does it host its own microbiome? The question is important because, if the microbial colonization of humans occurs in the womb, it would have key implications for the shaping of the early immune system. Gordon Smith, a researcher in maternal fetal medicine, tells the Nature Podcast how he and his colleagues painstakingly determined that the placenta is sterile. And researcher Kjersti Aagaard, who co-authored an influential paper saying the contrary, explains why she sees those same results very differently.

Nature Podcast | 20 min listen

Reference: Nature paper

Get the expert view in the Nature News & Views article: No bacteria found in healthy placentas

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Disgraced financier Jeffrey Epstein used his wealth and influence to court leading scientists and involve them in discussions of his pet pseudoscience plans, reports The New York Times. Events that Epstein hosted at his mansion and private island (and in a submarine) involved Nobel prizewinners and members of the scientific elite — including Murray Gell-Mann, Stephen Hawking, Stephen Jay Gould, Oliver Sacks and George M. Church. Epstein’s aspirations included “seed[ing] the human race with his DNA” and “bankrolling efforts to identify a mysterious particle that might trigger the feeling that someone is watching you”.

The New York Times | 9 min read

Barbara Kiser’s pick of the top five science books to read this week includes environmental racism, the world as it isn’t, and a guided tour of the planets.

Nature | 3 min read