Stressed-out cells sometimes glow under fluorescent light. That phenomenon, a common problem for researchers using fluorescent microscopy, may be at the root of last year's sensational claims surrounding STAP cells, the supposedly powerful stem cells derived using a remarkably simple recipe. The STAP claims have been shown to be false, and the two Nature papers describing the cells have both been retracted. Now, researchers from seven labs have described what they saw when they tried to replicate the experiments in the weeks and months following the original publications. All report observations that may have misled the researchers who made the original claims, including cells that glow, faintly, under fluorescent light. The STAP team took this for evidence that key stem cell genes had been turned on, but more cautious researchers would have realized the glow was an artifact, the authors of the new paper say. To avoid a repeat of the STAP fiasco, leading stem cell scientists lay out criteria in another paper for future claims about new ways to derive stem cells. They suggest a range of tests that should help protect against both misleading assays and cell line contamination; before they publish, researchers should also demonstrate that the technique can be replicated in independent laboratories. Author: Gretchen Vogel

The hardest bit of your body is the enamel coating your teeth. But new analyses of fish fossils, as well as genetic analyses of a living fish species, suggest that this specialized material once served a very different function: to toughen some bones and scales of ancient fish. Well-preserved fossils of an ancient fish called Psarolepis romeri reveal that this 20-centimeter-long mini-predator, which prowled the seas between 410 million and 415 million years ago, had enamel in its scales and its skull--but not its teeth. The findings bolster earlier suggestions that ancient fish had armored scales, and they point to a new scenario for exactly how enamel ended up on teeth. Previously, researchers had suggested that over millions of years of evolution, hardened structures such as external scales gradually migrated into the mouth and changed shape to become teeth. But the patchy distribution of enamel in Psarolepis may suggest a different scenario, in which the pattern of enamel production, rather than the shape and location of already-enameled structures, shifted over time. Author: Sid Perkins

The director, author, and a NASA expert on how they balanced realism and movie magic Author: Meghna Sachdev

Next year, the National Institutes of Health (NIH) expects to begin recruiting at least 1 million people for what may become the world's largest study of how genes influence disease risks and drug responses. Plans for the study came into focus last week with the release of a blueprint from a panel of human geneticists, medical researchers, and other experts. It urged that NIH recruit participants not only through academic medical centers and health care organizations, but also by issuing an open invitation to anyone living in the United States. For NIH Director Francis Collins, the project, known as the Precision Medicine Initiative (PMI) Cohort Program, brings to fruition an idea he first proposed 11 years ago. But whether NIH can design and effectively manage such a massive endeavor remains an open question. Author: Jocelyn Kaiser

The geopolitical maneuvering in the South China Sea (SCS) is taking a heavy toll on the marine environment, scientists believe. The Spratly or Nansha Islands, a cluster of coral reefs and atolls, has become the focus of a territorial dispute between China and its neighbors. To the dismay of other countries bordering the SCS, China claims most of the sea, and it is bolstering its claims with a massive landfilling effort to transform some of the atolls into full-fledged islands. The scale and speed of the effort emerged earlier this month, when the Center for Strategic and International Studies in Washington, D.C., released high-resolution satellite photos showing that over the past 2 to 3 years, China has created 13 square kilometers of island area—abxzxout a quarter the size of Manhattan. In doing so, China has destroyed large areas of biodiverse reef that served as nurseries for fisheries throughout much of the SCS. Author: Christina Larson

The Scripps Research Institute has named two eminent scientists to lead one of the world's largest private biomedical research institutions. Scripps chemist Peter Schultz will serve as CEO, while Steve Kay, formerly a dean at the University of Southern California (USC), will serve as president. The announcement ends a contentious period between Scripps leadership and its faculty, who revolted a year ago when Scripps leaders attempted to merge the institute with USC. Schultz and Kay say they intend to marry the institute's historic strength in basic research with a new emphasis on translational research that aims to turn discoveries into medicines. If they succeed, the duo say, that should stabilize the institute's long-term finances. Author: Robert F. Service

The National Science Foundation's dream of building a continental-scale observatory that would monitor environmental change over decades is in trouble. The National Ecological Observatories Network (NEON), a unique string of 80-some data-collection stations spread from Alaska to Puerto Rico, is designed to bring ecology into the era of Big Data by collecting masses of information on changes in climate, land use, biodiversity, and the spread of invasive species. But NEON has suffered a series of self-inflicted and external wounds since construction began in 2011, resulting in project delays, a large projected cost overrun, and several changes in senior leadership. NSF officials have now warned project managers that they must shape up or risk being replaced. Author: Jeffrey Mervis

For many of NEON's 80-plus monitoring sites, getting the necessary permits to begin work was the biggest hurdle. But urban sites have posed special challenges because of a constellation of factors that affect construction and operations. One site in Puerto Rico was undone by a human tragedy. It also represented a loss of capacity for the project. Author: Jeffrey Mervis

Getting a job in ecology can be tough, but NEON arguably has been hiring more ecologists than anyplace else: Earlier this year its workforce topped some 400 permanent and 100 summer employees. But NEON's disarray has led to high turnover and taken a toll on promising careers. The turnover has also robbed NEON of talent that could help it overcome future challenges. Author: Jeffrey Mervis

Anthropogenic climate change is expected to increase the frequency of heat waves and other extreme weather events (1). When such an event occurs, it is natural to ask whether it can be attributed to human activities. Conventional wisdom has long held that although it is possible to attribute an increase in the frequency of extreme events to human activities, the same is not true of individual events. Recent studies that appear to identify the role of anthropogenic climate change in, among other events, the 2010 Russian heat wave (2), the 2013 Australian heat wave (3), and the ongoing drought in California (see the photo) (4) suggest that this conventional wisdom has been overturned. But has it? Author: Andrew R. Solow

The World Health Organization defines female genital cutting as any procedure that removes or injures any part of a female's external genitalia for nonmedical reasons (1). Cutting brings no documented health benefits and leads to serious health problems. Across six African countries, for example, a cohort of 15-year-old girls is expected to lose nearly 130,000 years of life because of cutting (2). We report data that question an influential approach to promoting abandonment of the practice. Authors: Charles Efferson, Sonja Vogt, Amy Elhadi, Hilal El Fadil Ahmed, Ernst Fehr

Cellular senescence is a state of “permanent” arrest of the cell division cycle. It is associated with hyperactivated secretion of proinflammatory factors and with a range of pathophysiological processes such as wound healing, aging, and cancer (1). The processes that control the senescence-associated secretory phenotype (SASP) are not well defined. One candidate effector mechanism is macroautophagy (herein referred to as autophagy), a major intracellular degradation system, but whether it promotes or inhibits senescence is disputed (2). On page 1503 of this issue, Kang et al. begin to unravel this paradox and provide new insights into the mechanisms by which the SASP is controlled (3). Authors: Liam D. Cassidy, Masashi Narita

Diseases caused by pathogenic mutations in mitochondrial DNA (mtDNA) often lead to severe, multisystem complications and death during childhood or adolescence, and in some cases, adult onset can lead to premature death. Researchers have proposed techniques to prevent the transmission of mtDNA disease through mtDNA replacement therapies that involve combining healthy nuclear and mtDNA from three individuals. This past February, the United Kingdom became the first country to legalize mtDNA replacement (the United States continues to consider the ethical and social implications). Although mitochondrial and nuclear genomes are physically separate in the cell, they work together functionally to control various metabolic and developmental processes, including energy production, cell growth, programmed cell death, and thermogenesis. This intergenomic relationship raises questions about possible effects of different mtDNAs (those that are not the original mtDNAs in a given cell) on cellular bioenergetics and disease susceptibility (see the figure). Recent studies in mice that have examined this issue suggest that different mtDNA and nuclear DNA combinations could plausibly have differential effects on gene expression and cell function. Authors: Kimberly J. Dunham-Snary, Scott W. Ballinger

The quantum Hall effect is a hallmark of topological physics. It is the first example in which the topology of the system determines a macroscopic phenomenon, the quantization of Hall conductance. In a seminal paper, Halperin related it to the existence of skipping orbits for the electrons at the edge of the sample (1). Although the Hall conductivity is nowadays routinely measured with high precision and used to define the SI unit of electrical resistance, observation of the underlying skipping orbits has been elusive. On pages 1514 and 1510 of this issue, Stuhl et al. (2) and Mancini et al. (3) report a striking visualization of these trajectories using ultracold atoms trapped in a synthetic lattice. Authors: Alessio Celi, Leticia Tarruell

Redox flow batteries (RFBs) have many advantages for grid-level energy storage, a key requirement for implementing intermittent renewable sources. Like other rechargeable batteries, a flow battery uses reversible electrochemical couples on two electrodes to store chemical energy (1). However, instead of storing the active materials within the electrodes, the reactants are dissolved in two electrolyte solutions and stored in external tanks (see the figure). This configuration allows their cost to scale better as size increases compared to conventional batteries. To date, the redox-active species have often been transition-metal ions, which can have limited electrochemical potential range. On page 1529 of this issue, Lin et al. (2) report on the use of transition-metal complexes and organic molecules as redox species that are both low in cost and relatively nontoxic. Author: Mike L. Perry

Steve Silberman's book, NeuroTribes, blows many common beliefs about autism out of the water. Along the way, it tells the real stories of children and adults with autism, their families, and the clinicians and researchers trying to understand their very different minds. Reviewer Francesca Happé recounts the fascinating history of the autism story, and praises the book's affectionate and insightful portraits of autistic individuals, parents, and researchers. Author: Francesca Happé

George Annas and Sherman Elias, two longtime experts on the medical and social implications of genetics, wrote Genomic Messages to help people figure out how they should use genomic technologies to manage their health and the health of their families. Useful real and hypothetical cases stemming from Elias's practice as a medical geneticist pepper the book's chapters. Reviewer Henry T. Greely praises the authors' efforts to make genomic information accessible to a lay audience, but questions the ambitious scope of the book. Author: Henry T. Greely

A listing of books received at Science during the week ending 18 September 2015.

Author: Lon L. Hood

Authors: Greg H. Rau, Charles H. Greene