Atypical radio pulsations from magnetar SGR 1935+2154

Magnetars are neutron stars with extremely strong magnetic fields, frequently powering high-energy activity in X-rays. Pulsed radio emission following some X-ray outbursts have been detected, albeit its physical origin is unclear. It has long been speculated that the origin of magnetars' radio signals is different from those from canonical pulsars, although convincing evidence is still lacking. Five months after magnetar SGR 1935+2154's X-ray outburst and its associated Fast Radio Burst (FRB) 20200428, a radio pulsar phase was discovered. Here we report the discovery of X-ray spectral hardening associated with the emergence of periodic radio pulsations from SGR 1935+2154 and a detailed analysis of the properties of the radio pulses. The complex radio pulse morphology, which contains both narrow-band emission and frequency drifts, has not been seen before in other magnetars, but is similar to those of repeating FRBs - even though the luminosities are many orders of magnitude different. The observations suggest that radio emission originates from the outer magnetosphere of the magnetar, and the surface heating due to the bombardment of inward-going particles from the radio emission region is responsible for the observed X-ray spectral hardening.Comment: 47 pages, 11 figure

Teacher Leadership in State Education Policy

There is a national call for teacher leadership, which has occurred after many education reforms have struggled due to a perceived lack of teacher involvement. The purpose of this study was to examine whether teachers felt that their involvement in education policy had impact and whether there is ample teacher expertise in education policy. The overarching research question was to appraise educator perceptions of teacher impact on state education policy. The study revealed a perceived lack of teacher impact and education expertise. The conceptual framework was based on theories of adult learning and the development of expertise and supported the necessity of teacher expertise in policy discussions\u27 because teachers are the ones who have developed classroom expertise and the potential impact of policy on classrooms. A case study methodology was applied with 5 state teachers of the year participants. The participants were from 4 states, recognized from 2012-2015, and had local, state, and national policy experience. Interviews were conducted to collect data, with direct interpretation and categorical aggregation through coding applied to analyze data during collection. After identifying a perceived lack of teacher impact, themes were identified that could create more effective impact. Themes were grouped into skills, knowledge, and dispositions that could be taught in a series of learning experiences, serving as curriculum for teachers to build expertise in policy. This project has the potential to assist educators in developing the skills, knowledge, and dispositions needed to become more effectively involved in policy. It also has the potential to create social change in the United States by assisting teachers in getting meaningfully involved in policy, thereby positively impacting public education for their students in their classrooms, schools, districts, and beyond

Adaptive Mechanisms of an Estuarine Synechococcus based on Genomics, Transcriptomics, and Proteomics

Picocyanobacteria are important phytoplankton and primary producers in the ocean. Although extensive work has been conducted for picocyanobacteria (i.e. Synechococcus and Prochlorococcus) in coastal and oceanic waters, little is known about those found in estuaries like the Chesapeake Bay. Synechococcus CB0101, an estuarine isolate, is more tolerant to shifts in temperature, salinity, and metal toxicity than coastal and oceanic Synechococcus strains, WH7803 and WH7805. Further, CB0101 has a greater sensitivity to high light intensity, likely due to its adaptation to low light environments. A complete and annotated genome sequence of CB0101 was completed to explore its genetic capacity and to serve as a basis for further molecular analysis. Comparative genomics between CB0101, WH7803, and WH7805 show that CB0101 contains more genes involved in regulation, sensing, and stress response. At the transcript and protein level, CB0101 regulates its metabolic pathways, transport systems, and sensing mechanisms when nitrate and phosphate are limited. Zinc toxicity led to oxidative stress and a global down regulation of photosystems and the translation machinery. From the stress response studies seven chromosomal toxin-antitoxin (TA) genes, were identified in CB0101, which led to the discovery of TA genes in several marine Synechococcus strains. The activation of the relB2/relE1 TA system allows CB0101 to arrest its growth under stressful conditions, but the growth arrest is reversible, once the stressful environment dissipates. The genome of CB0101 contains a relatively large number of genomic island (GI) genes compared to known marine Synechococcus genomes. Interestingly, a massive shutdown (255 out of 343) of GI genes occurred after CB0101 was infected by a lytic phage. On the other hand, phage-encoded host-like proteins (hli, psbA, ThyX) were highly expressed upon phage infection. This research provides new evidence that estuarine Synechococcus like CB0101 have inherited unique genetic machinery, which allows them to be versatile in the estuarine environment