Results 41 to 50 of about 583,316 (279)

Selection of Design Parameters in Optical System of Star Tracker for a Satellite [PDF]

open access: yesJournal of Astronomy and Space Sciences, 1999
In order to develop star trackers for a satellite in our country we studied selection procedure of optical parameters. For logical selection of the optical parameters, we simulated the entire processes in which star lights imaged on a CCD sensor were ...
Ja-Kyung Nah, Yong Ha Kim, Yu Yi
doaj  

Residual tail twisting in ascidian larvae is stabilized by asymmetric myofibrils that resist bilateral symmetry restoration

open access: yesFEBS Letters, EarlyView.
Ascidian Ciona larvae initially show strong clockwise tail twisting, which is largely corrected during development. However, a small residual twist remains. This study shows that organized helical myofibrils in tail muscles mechanically stabilize this residual asymmetry, preventing complete restoration of bilateral symmetry and revealing how embryos ...
Yuki S. Kogure   +3 more
wiley   +1 more source

Biophysical approaches for studying viral entry

open access: yesFEBS Letters, EarlyView.
Viruses infect all living organisms and have been responsible for major epidemics and pandemics. Their ongoing evolutionary battle with host defenses creates a constant need for improved tools to study viral behavior. Advancing methods to probe viral attachment, fusion, and genome release deepen our understanding of how infections begin and support the
Inbar Yosibash, Raya Sorkin
wiley   +1 more source

Salmonella lipopolysaccharide‐containing supported lipid bilayers as platforms to study bacteriophage interactions

open access: yesFEBS Letters, EarlyView.
We present robust protocols for the preparation of supported lipid bilayers (SLBs) incorporating either Salmonella smooth LPS or outer membrane vesicles (OMVs). We use a combination of quartz crystal microbalance with dissipation (QCM‐D) and fluorescence microscopy to both characterize the SLBs of various compositions and to probe their interactions ...
Hudson P. Pace   +6 more
wiley   +1 more source

The MONS Star Trackers

open access: yes, 2000
The MONS satellite will have two Star Trackers to sense the spacecraft attitude, and we plan to use them as scientific instruments to perform high-precision photometry of thousands of stars. We briefly describe the current plans for the Star Trackers and their expected capabilities.
Bedding, Timothy R., Kjeldsen, Hans
openaire   +2 more sources

A comparison of star identification algorithms for star trackers [PDF]

open access: yes
Star trackers are the most accurate attitude-determination systems for satellites. Its operation is based on the identification of the stars present in the field of view of a small telescope and the determination of the astronomical coordinates of the centre of the image.
Jurado Aguilera, Sara
openaire   +2 more sources

From mice to humans—divergent strategies for intestinal homeostasis and regeneration

open access: yesFEBS Letters, EarlyView.
Recent advances such as organoid genome editing, xenotransplantation, imaging, and whole‐genome sequencing have enabled direct studies of human intestinal stem cells (ISCs). These studies reveal species‐specific features, including slower ISC proliferation, distinct injury responses, slower somatic mutation accumulation in humans, and an inverse ...
Keiko Ishikawa   +2 more
wiley   +1 more source

Design and analysis strategies for robust microbiome ageing research

open access: yesFEBS Letters, EarlyView.
The gut microbiome changes with age and associates with age‐related morbidity and mortality, establishing it as a potential biomarker and intervention target for ageing. Realising this potential requires methodological rigour, yet distinguishing biological signals from methodological artefacts remains challenging across cohorts. This review provides an
Mark Olenik   +5 more
wiley   +1 more source

Online calibration for star trackers [PDF]

open access: yes, 2021
Star trackers are perhaps the most accurate means of measuring a spacecraft's orientation in space and are becoming a popular sensing instrument for attitude determination systems amongst conventional larger satellites as well as micro satellites. In order to produce and maintain high fidelity measurements, the systematic effects of lens distortion and
openaire   +1 more source

Application of maximum likelihood techniques to the design of optimum star trackers [PDF]

open access: yes, 1968
Maximum likelihood techniques for design of optimum star trackers that determine position and ...
Foudriat, E. C.
core  

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