764 24 AUGUST 2018 • VOL 361 ISSUE 6404 sciencemag.org SCIENCE IMAGE: ESA–D. DUCROS, 2013 BLOOD A turbulent way to make platelets Donations from volunteers are the only source of blood for trans- fusions. But blood components such as platelets have a shelf life of only 5 days, and alterna- tive sources of platelets are in demand. By visualizing fluores- cently tagged megakaryocytes (precursor cells of platelets) in transgenic mice, Ito et al. dem- onstrated that highly turbulent blood flow is a determining factor of platelet production from mega- karyocytes. Turbulence triggered the production of thrombopoietic factors from megakaryocytes, which, along with shear stress, stimulated platelet release. By using a turbulence-controllable bioreactor, functionally viable platelets could be generated from megakaryocytes derived from human-induced pluripotent stem cells at a quantity that satisfies clinical-scale demand, suggesting the possibility of de novo platelet production as an alternative to acquiring platelets through blood donations. —MY Cell 174, 636 (2018). INFECTIOUS DISEASE Zika in the testes: A Trojan horse Zika virus (ZIKV) is a mosquito- borne flavivirus that can also be sexually transmitted. Although people infected with ZIKV are often asymptomatic, there is an association between ZIKV infection in pregnant women and severe birth defects in their chil- dren. Matusali et al. showed that ZIKV can replicate for several days in testicular tissue explants. ZIKV infects testicular somatic cells, germ cells, and spermato- zoa, and its presence has been detected in semen samples from ZIKV-infected patients. Despite Edited by Sacha Vignieri and Jesse Smith IN OTHER JOURNALS because of the protein’s wide- spread role in multiple tissues and organs. Cuchet-Lourenço et al. studied patients with inherited immunodeficiency of unknown cause (see the Perspective by Pasparakis and Kelliher). They identified inactivating mutations in the RIPK1 gene in four individu- als. Unlike what has been seen in mice, the deleterious effects of RIPK1 loss in humans were confined to the immune system, a finding with potential therapeutic implications. —PAK Science, this issue p. 810; see also p. 756 SOCIAL ROBOTICS Robots help autistic kids interact with adults Children with autism spectrum disorder (ASD) often struggle with social behaviors such as recognizing emotional responses in others and understanding gaze direction. Scassellati et al. put a fully autonomous, adap- tive robot in the homes of 12 children with ASD for 1 month to help improve the children’s social skills. The robot and a caregiver engaged with each child for 30 minutes every day, playing games that involved activities such as emotional storytelling and taking another’s perspective. The robot autonomously adapted task diffi- culty to each child’s performance and modeled appropriate gaze directions. The children showed improvements in attention skills and, crucially, demonstrated the improvements while interacting with adults even when the robot was not present. —RLK Sci. Robot. 3, eaat7544 (2018). GAS GIANT PLANETS Moons drive structure in Jupiter’s aurorae Like Earth, Jupiter has aurorae generated by energetic particles hitting its atmosphere. Those incoming particles can come from Jupiter’s moons Io and Ganymede. Mura et al. used infrared observations from the Juno spacecraft to image the moon-generated aurorae. The pattern induced by Io showed an alternating series of spots, reminiscent of vortices, and sometimes split into two arcs. Aurorae related to Ganymede could also show a double struc- ture. Although the cause of these unexpected features remains unknown, they may provide a way to examine how the moons produce energetic particles or how the particles propagate to Jupiter. —KTS Science, this issue p. 774 PROTEOMICS The blood proteome in disease Understanding the function of human blood serum proteins in disease has been limited by difficulties in monitoring their production, accumulation, and distribution. Emilsson et al. inves- tigated human serum proteins of more than 5000 Icelanders over the age of 65. The composition of blood serum includes a complex regulatory network of proteins that are globally coordinated across most or all tissues. The authors identified modules and functional groups associated with disease and health outcomes and were able to link genetic variants to complex diseases. —LMZ Science, this issue p. 769 GRAPHENE An electronic wedding cake In nanostructures such as quan- tum dots, spatial confinement forces electrons to assume dis- crete energy levels. Quantization can also occur in an external magnetic field, where electrons’ energies group into so-called Landau levels (LLs). Gutiérrez et al. explored the interplay between these two mechanisms and elec- tronic interactions in a circulator resonator made of graphene. As an external magnetic field was increased, the electron quantum states transformed from atomic- like states to LL-like states. Electronic interactions caused a characteristic wedding cake–like shape of electronic density at high fields. —JS Science, this issue p. 789 Artist’s rendering of the Gaia spacecraft STELLAR EVOLUTION A population of merged white dwarfs W hite dwarfs are the hot exposed cores left over when a dying low-mass star throws off its outer layers. The Gaia spacecraft recently provided accurate distances to more than a hundred times as many white dwarfs than were previously available, allow- ing detailed studies of the population. Kilic et al. investigated the mass and composition of these white dwarfs and reproduced them with stellar evolu- tion models. They show that about 15% of the white dwarfs have higher- than-expected masses. This is a sign that they formed from mergers, either between two parent stars or two white dwarfs. —KTS Mon. Not. R. Astron. Soc. Lett. 479, L113 (2018). RESEARCH | IN SCIENCE JOURNALS Published by AAAS on July 9, 2021 http://science.sciencemag.org/ Downloaded from