4,833 research outputs found
Mark 4A DSN receiver-exciter and transmitter subsystems
The present configuration of the Mark 4A DSN Receiver-Exciter and Transmitter Subsystems is described. Functional requirements and key characteristics are given to show the differences in the capabilities required by the Networks Consolidation task for combined High Earth Orbiter and Deep Space Network tracking support
The microprocessor-based synthesizer controller
Implementation and performance of the microprocessor-based controllers and Dana Digiphase Synthesizer (DCO) installed in the Deep Space Network exciter in the 64-meter and 34-meter subnets to support uplink tuning required for the Voyager-Saturn Encounter is discussed. Test data in tests conducted during the production of the controllers verified the design objective for phase control accuracy of 10 to the - 12 power cycles in eight hours during ramping. Tests conducted require a phase error between a theoretical calculated value and the actual phase of no greater than + or - 1 cycle. Tests included (1) a ramp over a period of eight hours using a ramp rate which covers the synthesizer tuning range (40-51 MHz) and (2) a ramp sequence using the maximum rate (+ or kHz/s) over the tuning range
Neutrino Physics: an Update
We update our recent didactic survey of neutrino physics, including new
results from the Sudbury Neutrino Observatory and KamLAND experiments, and
recent constraints from WMAP and other cosmological probes.Comment: latex; 19 pages; five figure
Neutrino Physics
The basic concepts of neutrino physics are presented at a level appropriate
for integration into elementary courses on quantum mechanics and/or modern
physics.Comment: Prepared for the American Journal of Physics; 50 pages; 11 figures
(10 included); late
Potential Theory on Trees, Graphs and Ahlfors Regular Metric Spaces
We investigate connections between potential theories on a Ahlfors-regular
metric space X, on a graph G associated with X, and on the tree T obtained by
removing the "horizontal edges" in G. Applications to the calculation of set
capacity are given.Comment: 45 pages; presentation improved based on referee comment
Norwegian-American Debating Societies: A Historical and Rhetorical Analysis
The purpose of this study was to investigate two Norwegian-American debating societies: the Forward Debate Society, founded in 1889, and the Wig Debate Society, founded in 1890. Both societies were in Minnesota. The study included a brief history of the self-improvement movement that eventually paved the way for immigrant debate societies, and an analysis of each society using three criteria: the categories of the topics debated, the annual pattern in which the debates occurred, and the type of propositions that were debated. These immigrant debate societies provided an atmosphere conducive to learning and helped to ease the assimilation process. Through debate, the members were able to question various issues and ultimately become civically responsible citizens
Multilingualism in its Social Context in Aboriginal North America
Proceedings of the 4th Annual Meeting of the Berkeley Linguistics
Society (1978), pp. 610-61
From Hadrons to Nuclei: Crossing the Border
The study of nuclei predates by many years the theory of quantum
chromodynamics. More recently, effective field theories have been used in
nuclear physics to ``cross the border'' from QCD to a nuclear theory. We are
now entering the second decade of efforts to develop a perturbative theory of
nuclear interactions using effective field theory. This work describes the
current status of these efforts.Comment: 141 pages, 58 figs, latex. To appear in the Boris Ioffe Festschrift,
ed. by M. Shifman, World Scientifi
Morphology of the Reproductive System of Tetrix arenosa angusta (Hancock) (Orthoptera, Tetrigidae)
The internal reproductive organs of the male include a pair of testes, each composed of about 37 follicles and connected to a short vas efferens; a pair of vasa deferentia; about 12 paired accessory glands; a twice folded ejaculatory duct and a membranous, extensible intromittent organ. The external structures of the male include a chitinous collar, pallial complex and ninth abdominal sternum. The internal reproductive organs of the female include a pair of ovaries, each composed of 11 ovarioles; paired lateral oviducts; a short median oviduct; a terminal genital chamber; a trilobed spermatheca attached to a spermathecal gland, and a pair of median glands. The external structures of the female include the ovipositor and its related sclerites and apodemes
Benchmarking of long-read assemblers for prokaryote whole genome sequencing.
Background: Data sets from long-read sequencing platforms (Oxford Nanopore Technologies and Pacific Biosciences) allow for most prokaryote genomes to be completely assembled - one contig per chromosome or plasmid. However, the high per-read error rate of long-read sequencing necessitates different approaches to assembly than those used for short-read sequencing. Multiple assembly tools (assemblers) exist, which use a variety of algorithms for long-read assembly. Methods: We used 500 simulated read sets and 120 real read sets to assess the performance of eight long-read assemblers (Canu, Flye, Miniasm/Minipolish, NECAT, NextDenovo/NextPolish, Raven, Redbean and Shasta) across a wide variety of genomes and read parameters. Assemblies were assessed on their structural accuracy/completeness, sequence identity, contig circularisation and computational resources used. Results: Canu v2.1 produced reliable assemblies and was good with plasmids, but it performed poorly with circularisation and had the longest runtimes of all assemblers tested. Flye v2.8 was also reliable and made the smallest sequence errors, though it used the most RAM. Miniasm/Minipolish v0.3/v0.1.3 was the most likely to produce clean contig circularisation. NECAT v20200803 was reliable and good at circularisation but tended to make larger sequence errors. NextDenovo/NextPolish v2.3.1/v1.3.1 was reliable with chromosome assembly but bad with plasmid assembly. Raven v1.3.0 was reliable for chromosome assembly, though it did not perform well on small plasmids and had circularisation issues. Redbean v2.5 and Shasta v0.7.0 were computationally efficient but more likely to produce incomplete assemblies. Conclusions: Of the assemblers tested, Flye, Miniasm/Minipolish, NextDenovo/NextPolish and Raven performed best overall. However, no single tool performed well on all metrics, highlighting the need for continued development on long-read assembly algorithms
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