Results 91 to 100 of about 32,070 (302)

Identification of the plant mitochondrial OrfX protein: A mass spectrometry approach

open access: yesFEBS Letters, EarlyView.
The mitochondrial genome of plants contains an open reading frame, orfx, which encodes a rare protein that has so far escaped mass spectrometric detection. The protein resembles the c‐subunit of bacterial twin‐arginine‐motif‐dependent protein translocases (TatC).
Matthias Döring   +3 more
wiley   +1 more source

Generation of optimal trajectories for Earth hybrid pole sitters [PDF]

open access: yes, 2011
A pole-sitter orbit is a closed path that is constantly above one of the Earth's poles, by means of continuous low thrust. This work proposes to hybridize solar sail propulsion and solar electric propulsion (SEP) on the same spacecraft, to enable such a ...
Colin R. McInnes   +5 more
core   +1 more source

Low-Thrust Transfer Design of Low-Observable Geostationary Earth Orbit Satellite

open access: yesInternational Journal of Aerospace Engineering, 2015
With radar and surface-to-air missiles posing an increasing threat to on-orbit spacecraft, low-observable satellites play an important role in low-thrust transfers.
Bing Hua, Zhujun Shao
doaj   +1 more source

EDNRB‐dependent endothelin signaling reduces proliferation and promotes proneural‐to‐mesenchymal transition in gliomas

open access: yesMolecular Oncology, EarlyView.
Glioma cells mainly express the endothelin receptor EDNRB, while EDNRA is restricted to a perivascular tumor subpopulation. Endothelin signaling reduces glioma cell proliferation while promoting migration and a proneural‐to‐mesenchymal transition associated with poor prognosis. This pathway activates Ca2+, K+, ERK, and STAT3 signalings and is regulated
Donovan Pineau   +36 more
wiley   +1 more source

Low Earth Orbiting (LEO) Satellite and Orbital Decay

open access: yesInternational Journal of Engineering and Advanced Technology, 2022
In this article we present a simple but elegant numerical calculation to study the motion of a low earth orbiting (LEO) satellite in gravitational potential and under the influence of quadratic drag force. We solve a set of coupled differential equations to calculate the instantaneous position and velocity of the satellite and calculate the change in ...
openaire   +1 more source

Somatic mutational landscape in von Hippel–Lindau familial hemangioblastoma

open access: yesMolecular Oncology, EarlyView.
The causes of central nervous system (CNS) hemangioblastoma in Von Hippel–Lindau (vHL) disease are unclear. We used Whole Exome Sequencing (WES) on familial hemangioblastoma to investigate events that underlie tumor development. Our findings suggest that VHL loss creates a permissive environment for tumor formation, while additional alterations ...
Maja Dembic   +5 more
wiley   +1 more source

Observation of two distinct cold, dense ion populations at geosynchronous orbit: Local time asymmetry, solar wind dependence and origin [PDF]

open access: yes, 2006
International audienceWe report on the observation of two distinct cold (TiNi>2 cm?3) ion populations at geosynchronous orbit. A statistical study was performed on measurements from the geosynchronous Los Alamos plasma instruments, for the period 1990 ...
Aasnes, A.   +17 more
core   +1 more source

Enhanced Real-Time Onboard Orbit Determination of LEO Satellites Using GPS Navigation Solutions with Signal Transit Time Correction

open access: yesAerospace
Enhanced real-time onboard orbit determination for low-Earth-orbit satellites is essential for autonomous spacecraft operations. However, the accuracy of such systems is often limited by signal propagation delays between GPS satellites and the user ...
Daero Lee, Soon Sik Hwang
doaj   +1 more source

Thermal deformation of 3U CubeSat in low Earth orbit

open access: yesMATEC Web of Conferences, 2018
The impact of uneven heating on a satellite structure in low Earth orbit has been considered using the example of 3U CubeSat. The calculations showed that the thermal deformation of CubeSat structure in orbit caused a deviation between normals to ...
Gorev Vasily   +3 more
doaj   +1 more source

Autonomous Formation Flying in Low Earth Orbit [PDF]

open access: yes, 2010
Formation flying is commonly identified as the collective usage of two or more cooperative spacecraft to exercise the function of a single monolithic virtual instrument. The distribution of tasks and payloads among fleets of coordinated smaller satellites offers the possibility to overcome the classical limitations of traditional single-satellite ...
openaire   +3 more sources

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