Case study of radio emission beam associated to very low frequency signal recorded onboard CSES satellite

We report on the variation of electric power density linked to very low frequency (VLF) signal observed during the minimum of solar cycle 25. The detected VLF signal is emitted by the NWC radio station localized in the southern hemisphere, at 21.5∘ S and 114.2∘ E. We attempt in this work to quantify the beam as detected by the Electric Field Detector (EFD) instrument onboard CSES satellite. Geometrical key parameters have been considered to analysis the variation of the power density taking into consideration the distance between the satellite trajectory and the NWC station and its conjugate region. The beam behavior is found to be subject to significant disturbances in the conjugate region with the presence of signal modulations. Above the NWC transmitter station, the beam can be considered as a hollow cone but with irregularity dependence on the electric power density.</p

Impact of facial conformation on canine health: Brachycephalic Obstructive Airway Syndrome

The domestic dog may be the most morphologically diverse terrestrial mammalian species known to man; pedigree dogs are artificially selected for extreme aesthetics dictated by formal Breed Standards, and breed-related disorders linked to conformation are ubiquitous and diverse. Brachycephaly–foreshortening of the facial skeleton–is a discrete mutation that has been selected for in many popular dog breeds e.g. the Bulldog, Pug, and French Bulldog. A chronic, debilitating respiratory syndrome, whereby soft tissue blocks the airways, predominantly affects dogs with this conformation, and thus is labelled Brachycephalic Obstructive Airway Syndrome (BOAS). Despite the name of the syndrome, scientific evidence quantitatively linking brachycephaly with BOAS is lacking, but it could aid efforts to select for healthier conformations. Here we show, in (1) an exploratory study of 700 dogs of diverse breeds and conformations, and (2) a confirmatory study of 154 brachycephalic dogs, that BOAS risk increases sharply in a non-linear manner as relative muzzle length shortens. BOAS only occurred in dogs whose muzzles comprised less than half their cranial lengths. Thicker neck girths also increased BOAS risk in both populations: a risk factor for human sleep apnoea and not previously realised in dogs; and obesity was found to further increase BOAS risk. This study provides evidence that breeding for brachycephaly leads to an increased risk of BOAS in dogs, with risk increasing as the morphology becomes more exaggerated. As such, dog breeders and buyers should be aware of this risk when selecting dogs, and breeding organisations should actively discourage exaggeration of this high-risk conformation in breed standards and the show ring

Über eine Klasse polynomialer Scharen selbstadjungierter Operatoren im Hilbertraum

HEK293A cells expressing either mouse MOG (mMOG) or rat MOG (rMOG) C terminally tagged with EGFP. (DOCX 2792 kb

Design and test of the optical fiber assemblies for the scalar magnetic field sensor aboard the JUICE mission

A set of optical fiber assemblies has been developed and successfully qualified for its use on a European space science mission to the icy moons of Jupiter (Jupiter Icy Moons Explorer, JUICE), to be launched in 2022. The paper gives an overview of the design challenges, the test methods used for failure detection and screening of the optical fiber cable assemblies as well as the further testing performed in the frame of a lot acceptance qualification

A multiple-rendezvous, sample-return mission to two near-Earth asteroids

International audienceWe propose a dual-rendezvous mission, targeting near-Earth asteroids, including sample-return. The mission, Asteroid Sampling Mission (ASM), consists of two parts: (i) flyby and remote sensing of a Q-type asteroid, and (ii) sampling of a V-type asteroid. The targeted undifferentiated Q-type are found mainly in the near-Earth space, and to this date have not been the target of a space mission. We have chosen, for our sampling target, an asteroid from the basaltic class (V-type), as asteroids in this class exhibit spectral signatures that resemble those of the well-studied Howardite-Eucrite-Diogenite (HED) meteorite suite. With this mission, we expect to answer specific questions about the links between differentiated meteorites and asteroids, as well as gain further insight into the broader issues of early Solar System (SS) evolution and the formation of terrestrial planets. To achieve the mission, we designed a spacecraft with a dry mass of less than 3 tonnes that uses electric propulsion with a solar-electric power supply of 15 kW at 1 Astronomical Unit (AU). The mission includes a series of remote sensing instruments, envisages landing of the whole spacecraft on the sampling target, and employs an innovative sampling mechanism. Launch is foreseen to occur in 2018, as the designed timetable, and the mission would last about 10 years, bringing back a 150 g subsurface sample within a small re-entry capsule. This paper is a work presented at the 2008 Summer School Alpbach,"Sample return from the Moon, asteroids and comets" organized by the Aeronautics and Space Agency of the Austrian Research Promotion Agency. It is co-sponsored by ESA and the national space authorities of its Member and Co-operating States, with the support of the International Space Science Institute and Austrospace

Satellite Measured Ionospheric Magnetic Field Variations over Natural Hazards Sites

Processes and threats related to natural hazards play an important role in the evolution of the Earth and in human history. The purpose of this study is to investigate magnetic field variations measured at low Earth orbit (LEO) altitudes possibly associated with earthquakes, volcanic eruptions, and artificial outbursts. We focus on two missions with well equipped magnetometer packages, the China Seismo-Electromagnetic Satellite (CSES) and ESA’s three spacecraft Swarm fleet. After a natural hazards survey in the context of this satellites, and consideration of external magnetospheric and solar influences, together with spacecraft interferences, wavelet analysed spatio-temporal patterns in ionospheric magnetic field variations related to atmospheric waves are examined in detail. We provide assessment of the links between specific lithospheric or near surface sources and ionospheric magnetic field measurements. For some of the diverse events the achieved statistical results show a change in the pattern between pre- and post-event periods, we show there is an increase in the fluctuations for the higher frequency (smaller scales) components. Our results are relevant to studies which establish a link between space based magnetic field measurements and natural hazards

Spring development and mitotic division pattern of a Cryptomonas sp. in an acidified lake.

The net population growth of one Cryptomonas species was studied in an acidified, clearwater Finnish lake at the end of May. The potential growth of the population was also estimated from the pattern and timing of nuclear and cellular division of the alga. The population started to grow when the temperature had risen from 8 to 11°C. Nuclear division in the vernal Cryptomonas population was well phased and happended solely at night. However, the type of division pattern observed, in which mitosis and cytokinesis overlapped, made it difficult to apply the mitotic index technique for measurements of growth rate in situ. These results emphasise the importance of accurate estimation of the duration of mitosis for this method of determining growth rate in situ

Meeting the Magnetic EMC Challenges for the In-Situ Field Measurements on the Juice Mission

International audienc

Metrology for long distance surveying – a joint attempt to improve traceabili - ty of long distance measurements

A number of applications, e.g., the estab ~ ishment of local ties at geodetic fundamental stations, but also the maintenance of surveillance networks require distance measurements over hundred metres or more with uncertainties at the millimetre level or even below. However, based on the current state of technology and understanding of perturbing influences, a measurement traceable to the Sl definition of the metere with such uncertainties is extremely challenging or even impossible. The accuracy of electrooptic distance metres (EDMs) on one hand is primarily limited by the imperfect knowledge of the index of refraction of air, the measurement uncertainty of distance measurements based on Global Navigation Satellite Systems (GNSS) is even more difficult to quantify. In a joint research projects of 12 European institutions, scientists from national metrology institutes have united with partners from geodesy to develop novel technological and methodical solutions to understand, to quantify better, and to reduce the uncertainty of this kind of measurements, in particular fostering traceability to the Sl unit metre. In case of optical distance metrology, refractivity-compensated primary and transfer standards will be developed and applied to reference baselines in Europe. Furthermore, completely novel approaches based on femtosecond laser sources will be explored and set up. In case of GNSS-based distance metrology, a systematic investigation of sources of uncertainty will performed, leading to a sound uncertainty budget. Two different near real-time 3D monitoring systems will be developed and compared at geodetic fundamental stations. The contribution wants to present the concept and the scientific and technological ideas of the project which starts on July 1st 2013, inviting the geodetic community to provide guidance and feedback