Centromere sequences in the genome are associated with the formation of kinetochores, where spindle microtubules grow in mitosis. Centromere sequences usually have long tandem repeats (satellites). In holocentric nematodes it is not clear how kinetochores are formed during mitosis; they are distributed throughout the chromosomes. For this reason it appeared of interest to study the satellites i...

We have searched the four brightest objects in the Kuiper Belt for the presence of satellites using the newly commissioned Keck Observatory Laser Guide Star Adaptive Optics system. Satellites are seen around three of the four objects: Pluto (whose satellite Charon is well-known and whose recently discovered smaller satellites are too faint to be detected), 2003 EL61 (where a second satellite is...

Using detailed mock galaxy redshift surveys we investigate to what extent the kinematics of large samples of satellite galaxies extracted from flux-limited surveys can be used to constrain halo masses. Unlike previous studies, which focussed only on satellites around relatively isolated host galaxies, we try to recover the average velocity dispersion of satellite galaxies in all haloes, as a fu...

In this paper, we study the scheduling problem arising from refuelling multiple satellites in a constellation. The satellites in the constellation are assumed to be capable of refuelling each other. The cost of the rendezvous maneuver between two satellites exchanging fuel is assumed to be negligible. The goal of this refuelling problem is to equalize the fuel stored among all satellites in the...

The increased on demand from orbiting satellites in operation according to the National Institute for Space Research’s satellite program has motivated continuous improvement safety in the planning of routine operations in order to ensure the integrity of satellites in orbit. Therefore, we propose a mathematical model based on artificial intelligence concepts, which uses algorithms developed for...

In 2015, the plan for global coverage by the Chinese BeiDou Navigation Satellite System was launched. Five global BeiDou experimental satellites (BeiDou-3e) are in orbit for testing. To analyze the performances of precise orbit determination (POD) and precise point positioning (PPP) of onboard BeiDou satellites, about two months of data from 24 tracking stations were used. According to quality ...

Gene expression differences between males and females often underlie sexually dimorphic phenotypes, and the expression levels of genes that are differentially expressed between the sexes are thought to respond to sexual selection. Most studies on the transcriptomic response to sexual selection treat sexual selection as a single force, but postmating sexual selection in particular is expected to...

We present a deep optical survey of Uranus’ Hill sphere for small satellites. The Subaru 8-m telescope was used to survey about 3.5 square degrees with a 50% detection efficiency at limiting red magnitude mR = 26.1 mag. This magnitude corresponds to objects that are about 7 km in radius (assuming an albedo of 0.04). We detected (without prior knowledge of their positions) all previously known o...

In this paper, we study the scheduling problem arising from refuelling multiple satellites in a constellation. It is assumed that there is no fuel delivered to the constellation externally. Instead, the satellites in the constellation are assumed to be capable of refuelling each other. The cost of the rendezvous maneuver between two satellites conducting a fuel transfer is taken into considerat...

Single-Frequency Single-Epoch (SFSE) high-precision positioning has always been the hot spot of Global Navigation Satellite System (GNSS), and ambiguity dilution of precision (ADOP) is a well-known scalar measure for success rate of ambiguity resolution. Traditional ADOP expression is complicated, thus the SFSE extended ADOP (E-ADOP), with the newly defined Summation-Multiplication Ratio of Wei...