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

Author: Enrique Guerra-Pujol

Jarvis et al. (Research Articles, 12 December 2014, p. 1320) presented molecular clock analyses that suggested that most modern bird orders diverged just after the mass extinction event at the Cretaceous-Paleogene boundary (about 66 million years ago). We demonstrate that this conclusion results from the use of a single inappropriate maximum bound, which effectively precludes the Cretaceous diversification overwhelmingly supported by previous molecular studies. Authors: Kieren J. Mitchell, Alan Cooper, Matthew J. Phillips

Mitchell et al. argue that divergence-time estimates for our avian phylogeny were too young because of an “inappropriate” maximum age constraint for the most recent common ancestor of modern birds and that, as a result, most modern bird orders diverged before the Cretaceous-Paleogene mass extinction event 66 million years ago instead of after. However, their interpretations of the fossil record and timetrees are incorrect. Authors: Joel Cracraft, Peter Houde, Simon Y. W. Ho, David P. Mindell, Jon Fjeldså, Bent Lindow, Scott V. Edwards, Carsten Rahbek, Siavash Mirarab, Tandy Warnow, M. Thomas P. Gilbert, Guojie Zhang, Edward L. Braun, Erich D. Jarvis

Neuroscience has shed light on the struggle, but early intervention and cost remain challenges Author: Gavin Stern

Author: Gavin Stern