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30/06/2024

SANTé/MEDECINE - Anatomie du coeur humain -


À gauche, la valve mitrale a été remplacée par une valve artificielle. Cette opération est souvent nécessaire en cas de malformation de la valve auriculo-ventriculaire ou suite à une insuffisance valvulaire (défaut de fermeture de la valve). À droite, un pontage coronarien permet de contourner une artère coronaire bouchée et d'apporter du sang riche en oxygène au muscle cardiaque, grâce à un vaisseau greffé. Ce vaisseau greffé provient souvent de la jambe.

© 2018 Patrick Lynch

ASTRONOMY - Earthrise: A Video Reconstruction

 2024 June 30

Earthrise: A Video Reconstruction
Video Credit: NASASVSApollo 8 Crew;
Lead Animator: Ernie Wright; (USRA); Music: C Major Prelude by Johann Sebastian Bach

Explanation: About 12 seconds into this video, something unusual happens. The Earth begins to rise. Never seen by humans before, the rise of the Earth over the limb of the Moon occurred about 55.5 years ago and surprised and amazed the crew of Apollo 8. The crew immediately scrambled to take still images of the stunning vista caused by Apollo 8's orbit around the Moon. The featured video is a modern reconstruction of the event as it would have looked were it recorded with a modern movie camera. The colorful orb of our Earth stood out as a familiar icon rising above a distant and unfamiliar moonscape, the whole scene the conceptual reverse of a more familiar moonrise as seen from Earth. To many, the scene also spoke about the unity of humanity: that big blue marble -- that's us -- we all live there. The two-minute video is not time-lapse -- this is the real speed of the Earth rising through the windows of Apollo 8. Seven months and three missions later, Apollo 11 astronauts would not only circle Earth's moon, but land on it.

29/06/2024

SANTé/MEDECINE - Anatomie du coeur - Pseudo-anévrisme du ventricule gauche


Un pseudo-anévrisme, aussi appelé faux anévrisme, est une poche de sang qui se forme près du myocarde. Contrairement aux vrais anévrismes, il ne possède pas d'éléments du myocarde, mais risque de se rompre. Les pseudo-anévrismes du ventricule gauche sont rares, mais il s'agit souvent d'une complication d'un infarctus du myocarde. Ils peuvent aussi survenir après une opération cardiaque ou une infection.

© Patrick J. Lynch, CC by-sa 2.5

SANTé/MEDECINE - L'immortalité pour bientôt - Qui souhaite vivre éternellement ?


La grande question est de savoir si nous voulons vraiment vivre éternellement. Un immortel ne finirait-il pas par se lasser de l'existence humaine ? Seul le temps nous le dira.

©Fournis par The Daily Digest

ASTRONOMY - A Solstice Moon

2024 June 29
See Explanation.  Clicking on the picture will download
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A Solstice Moon
Image Credit & CopyrightTunc Tezel (TWAN)

Explanation: Rising opposite the setting Sun, June's Full Moon occurred within about 28 hours of the solstice. The Moon stays close to the Sun's path along the ecliptic plane and so while the solstice Sun climbed high in daytime skies, June's Full Moon remained low that night as seen from northern latitudes. In fact, the Full Moon hugs the horizon in this June 21 rooftop night sky view from Bursa, Turkey, constructed from exposures made every 10 minutes between moonrise and moonset. In 2024 the Moon also reached a major lunar standstill, an extreme in the monthly north-south range of moonrise and moonset caused by the precession of the Moon's orbit over an 18.6 year cycle. As a result, this June solstice Full Moon was at its southernmost moonrise and moonset along the horizon

28/06/2024

SANTé/MEDECINE - L'immortalité pour bientôt - Tout est donc dans la tête ?

Toutefois, il ne s'agirait que d'une copie numérique d'une personne, ce qui soulève de nouveaux dilemmes quant à l'existence de celle-ci et à la question de savoir si les machines ont une âme.

©Fournis par The Daily Digest

SANTé/MEDECINE - Anatomie du coeur humain - Coeur droit


Le cœur droit reçoit le sang pauvre en oxygène provenant des veines caves qui entre dans l'oreillette droite (ici sur la gauche de l'illustration). Le sang est mis sous pression dans le ventricule droit et est expulsé du cœur par les artères pulmonaires, pour rejoindre les poumons. Voyez la valve sigmoïde du tronc pulmonaire, formée de trois valvules en « croissants de lune ».

© Patrick J. Lynch, CC by-sa 2.5

ASTRONOMY - Comet 13P/Olbers

 2024 June 28

See Explanation.  Clicking on the picture will download
 the highest resolution version available.

Comet 13P/Olbers
Image Credit & CopyrightDan Bartlett`

Explanation: Not a paradox, Comet 13P/Olbers is returning to the inner Solar System after 68 years. The periodic, Halley-type comet will reach its next perihelion or closest approach to the Sun on June 30 and has become a target for binocular viewing low in planet Earth's northern hemisphere night skies. But this sharp telescopic image of 13P is composed of stacked exposures made on the night of June 25. It easily reveals shifting details in the bright comet's torn and tattered ion tail buffeted by the wind from an active Sun, along with a broad, fanned-out dust tail and slightly greenish coma. The frame spans over two degrees across a background of faint stars toward the constellation Lynx.

27/06/2024

MUSIQUE CLASSIQUE - Chopin - Fantaisie impromptue

"Fantaisie impromptue"

ASTRONOMY - Protostellar Outflows in Serpens

 2024 June 27

See Explanation.  Clicking on the picture will download
 the highest resolution version available.

Protostellar Outflows in Serpens
Image Credit: NASAESACSASTScI, Klaus Pontoppidan (NASA-JPL), Joel Green (STScI)

Explanation: Jets of material blasting from newborn stars, are captured in this James Webb Space Telescope close-up of the Serpens Nebula. The powerful protostellar outflows are bipolar, twin jets spewing in opposite directions. Their directions are perpendicular to accretion disks formed around the spinning, collapsing stellar infants. In the NIRcam image, the reddish color represents emission from molecular hydrogen and carbon monoxide produced as the jets collide with the surrounding gas and dust. The sharp image shows for the first time that individual outflows detected in the Serpens Nebula are generally aligned along the same direction. That result was expected, but has only now come into clear view with Webb's detailed exploration of the active young star-forming region. Brighter foreground stars exhibit Webb's characteristic diffraction spikes. At the Serpens Nebula's estimated distance of 1,300 light-years, this cosmic close-up frame is about 1 light-year across.

ASTRONOMY - Christmas Tree Aurora

 2024 December 23 Christmas Tree Aurora Image Credit & Copyright:  Jingyi Zhang Explanation:  It was December and the sky lit up like a ...