First Infrared Coronal Spectra from DKIST/Cryo-NIRSP: Comparisons with Global MHD Models

The Cryogenic Near-Infrared Spectropolarimeter (Cryo-NIRSP) is now conducting science operations at the National Science Foundation’s Daniel K. Inouye Solar Telescope (DKIST). We report results obtained during instrument commissioning that advance multiwavelength coronagraphic observations in the infrared. This includes the first observations of the Fe xiii 1075 nm, Fe xiii 1079 nm, Si x 1430 nm, and Si ix 3934 nm forbidden lines. The Si ix observations, in particular, significantly improve upon the few previous ground-based detections and open up this diagnostic for more routine study. We analyse long-slit spectra in each line sampling elongations from 1.06 to 1.52 solar radii above the northeast solar limb on 2022 February 14. Line characteristics as a function of radial distance are derived and discussed in comparison to modeled emission emergent from global coronal magnetohydrodynamic models with different heating prescriptions. We find favorable correspondence between the observations and different aspects of these models, and further demonstrate the utility of infrared observations for constraining coronal models. Continued DKIST/Cryo-NIRSP observations including polarimetric data, together with ongoing improvements in data calibrations, promise significant value for coronal studies

Light-Based Printing of Leachable Salt Molds for Facile Shaping of Complex Structures

3D printing is a powerful manufacturing technology for shaping materials into complex structures. While the palette of printable materials continues to expand, the rheological and chemical requisites for printing are not always easy to fulfill. Here, a universal manufacturing platform is reported for shaping materials into intricate geometries without the need for their printability, but instead using light-based printed salt structures as leachable molds. The salt structures are printed using photocurable resins loaded with NaCl particles. The printing, debinding, and sintering steps involved in the process are systematically investigated to identify ink formulations enabling the preparation of crack-free salt templates. The experiments reveal that the formation of a load-bearing network of salt particles is essential to prevent cracking of the mold during the process. By infiltrating the sintered salt molds and leaching the template in water, complex-shaped architectures are created from diverse compositions such as biomedical silicone, chocolate, light metals, degradable elastomers, and fiber composites, thus demonstrating the universal, cost-effective, and sustainable nature of this new manufacturing platform.Aerospace Manufacturing Technologie

miRNAs in ancient tissue specimens of the Tyrolean Iceman

The analysis of nucleic acids in ancient samples is largely limited to DNA. Small noncoding RNAs (microRNAs) are known to be evolutionary conserved and stable. To gain knowledge on miRNAs measured from ancient samples, we profiled microRNAs in cryoconserved mummies. First, we established the approach on a World War One warrior, the “Kaiserj€ager”, which has been preserved for almost one century. Then, we profiled seven ancient tissue specimens including skeletal muscle, stomach mucosa, stomach content and two corpus organ tissues of the 5,300-year-old copper age mummy Iceman and compared these profiles to the presence of organ-specific miRNAs in modern tissues. Our analyses suggest the presence of specific miRNAs in the different Iceman’s tissues. Of 1,066 analyzed human miRNAs, 31 were discovered across all biopsies and 87 miRNAs were detected only in a single sample. To check for potential microbiological contaminations, all miRNAs detected in Iceman samples and not present in ancient samples were mapped to 14,582 bacterial and viral genomes. We detected few hits (3.9% of miRNAs compared with 3.6% of miRNAs). Interestingly, the miRNAs with higher abundance across all ancient tissues were significantly enriched for Guanine (P value of 10–13) and Cytosine (P value of 10–7). The same pattern was observed for modern tissues. Comparing miRNAs measured from ancient organs to modern tissue patterns highlighted significant similarities, e.g., formiRNAs present in themuscle. Our first comprehensive analysis of microRNAs in ancient human tissues indicates that these stable molecules can be detected in tissue specimens after 5,300 years

Firefly: The Case for a Holistic Understanding of the Global Structure and Dynamics of the Sun and the Heliosphere

This white paper is on the HMCS Firefly mission concept study. Firefly focuses on the global structure and dynamics of the Sun's interior, the generation of solar magnetic fields, the deciphering of the solar cycle, the conditions leading to the explosive activity, and the structure and dynamics of the corona as it drives the heliosphere