2 research outputs found
STRAW-b (STRings for Absorption length in Water-b): the second pathfinder mission for the Pacific Ocean Neutrino Experiment
Since 2018, the potential for a high-energy neutrino telescope, named the
Pacific Ocean Neutrino Experiment (P-ONE), has been thoroughly examined by two
pathfinder missions, STRAW and STRAW-b, short for short for Strings for
Absorption Length in Water. The P-ONE project seeks to install a neutrino
detector with a one cubic kilometer volume in the Cascadia Basin's deep marine
surroundings, situated near the western shores of Vancouver Island, Canada. To
assess the environmental conditions and feasibility of constructing a neutrino
detector of that scale, the pathfinder missions, STRAW and STRAW-b, have been
deployed at a depth of 2.7 km within the designated site for P-ONE and were
connected to the NEPTUNE observatory, operated by Ocean Networks Canada (ONC).
While STRAW focused on analyzing the optical properties of water in the
Cascadia Basin, \ac{strawb} employed cameras and spectrometers to investigate
the characteristics of bioluminescence in the deep-sea environment. This report
introduces the STRAW-b concept, covering its scientific objectives and the
instrumentation used. Furthermore, it discusses the design considerations
implemented to guarantee a secure and dependable deployment process of STRAW-b.
Additionally, it showcases the data collected by battery-powered loggers, which
monitored the mechanical stress on the equipment throughout the deployment. The
report also offers an overview of STRAW-b's operation, with a specific emphasis
on the notable advancements achieved in the data acquisition (DAQ) system and
its successful integration with the server infrastructure of ONC.Comment: 20 pages, 11 figures, 2 table
\u3ci\u3eDrosophila\u3c/i\u3e Muller F Elements Maintain a Distinct Set of Genomic Properties Over 40 Million Years of Evolution
The Muller F element (4.2 Mb, ~80 protein-coding genes) is an unusual autosome of Drosophila melanogaster; it is mostly heterochromatic with a low recombination rate. To investigate how these properties impact the evolution of repeats and genes, we manually improved the sequence and annotated the genes on the D. erecta, D. mojavensis, and D. grimshawi F elements and euchromatic domains from the Muller D element. We find that F elements have greater transposon density (25–50%) than euchromatic reference regions (3–11%). Among the F elements, D. grimshawi has the lowest transposon density (particularly DINE-1: 2% vs. 11–27%). F element genes have larger coding spans, more coding exons, larger introns, and lower codon bias. Comparison of the Effective Number of Codons with the Codon Adaptation Index shows that, in contrast to the other species, codon bias in D. grimshawi F element genes can be attributed primarily to selection instead of mutational biases, suggesting that density and types of transposons affect the degree of local heterochromatin formation. F element genes have lower estimated DNA melting temperatures than D element genes, potentially facilitating transcription through heterochromatin. Most F element genes (~90%) have remained on that element, but the F element has smaller syntenic blocks than genome averages (3.4–3.6 vs. 8.4–8.8 genes per block), indicating greater rates of inversion despite lower rates of recombination. Overall, the F element has maintained characteristics that are distinct from other autosomes in the Drosophila lineage, illuminating the constraints imposed by a heterochromatic milieu