8 research outputs found
Quel est l'impact de l'indice de masse corporelle pré-gestationnel insuffisant et d'une prise de poids gestationnelle inférieure à la norme, notamment chez les femmes souffrant d'anorexie, sur le poids de naissance de l'enfant et la prématurité: travail de Bachelor
Introduction : Des prĂ©occupations autours de poids sont prĂ©sentes lors de grossesse chez beaucoup de femmes, notamment chez celle qui souffrent de troubles alimentaires. LâobĂ©sitĂ© et la prise de poids gestationnelle excessive sont aujourdâhui des problĂšmes de santĂ© dont les consĂ©quences sont bien connues tandis que les effets des phĂ©nomĂšnes inverses restent ambigus. Objectif : le but de cette revue de littĂ©rature Ă©tait de mettre en Ă©vidence les effets du souspoids prĂ©-gestationel et de la faible prise de poids gestationnelle [PDPG], notamment chez des femmes souffrant dâanorexie, sur la prĂ©maturitĂ© et le poids de naissance de lâenfant. MĂ©thode : Une revue systĂ©matique de la littĂ©rature scientifique a Ă©tĂ© Ă©laborĂ©e Ă partir de huit Ă©tudes sĂ©lectionnĂ©es, en fonction de critĂšres prĂ©cis, dans les bases de donnĂ©es de la littĂ©rature scientifique actuelle (CINHAL, Cochrane Database of Systematic Reviews, MEDLINE, MIDIRS). RĂ©sultats : Selon une Ă©tude, un indice de masse corporelle [IMC] prĂ©-gestationnel infĂ©rieur Ă la norme induirait une augmentation significative du risque dâaccoucher prĂ©maturĂ©ment comparĂ© Ă un IMC normal. Selon les Ă©tudes retenues qui traitaient de ce sujet, lâanorexie nâavait pas dâimpact sur la prĂ©maturitĂ© et nâaugmenterait pas les risques dâavoir un nourrisson petit pour lâĂąge gestationnel [SGA]. Trois Ă©tudes relevaient une augmentation du risque dâavoir un SGA chez les femmes en sous-poids, comparĂ©es aux femmes de poids normal. Une des Ă©tudes dĂ©montrait quâune PDPG insuffisante provoquait une augmentation du risque dâavoir un SGA, comparĂ©e Ă une PDPG adĂ©quate. Deux des Ă©tudes dĂ©montraient quâune PDPG insuffisante aggravait le taux de SGA chez les femmes en sous-poids. En effet, le sous-poids et la faible PDPG diminueraient le poids de naissance de lâenfant. Conclusion : Le rĂ©sultat principal qui ressort de cette revue de littĂ©rature est quâun IMC prĂ©gestationnel infĂ©rieur Ă la norme et une PDPG infĂ©rieure aux recommandations, influent, de façons indĂ©pendantes ou couplĂ©es, sur le poids de naissance du nouveau-nĂ©. Ainsi les femmes souffrant de sous-poids et les femmes ayant eu une faible PDPG, ont un taux plus Ă©levĂ© de SGA et dâenfant ayant un petit poids de naissance, comparĂ©es aux femmes de poids normal et ayant une PDPG dans les normes. Une attention toute particuliĂšre doit donc ĂȘtre mise en place quant au suivi des femmes en sous-poids et des femmes ayant une PDPG infĂ©rieure aux recommandations de lâIOM (2009), afin de mieux prendre en soins le nouveau-nĂ© et la femme
Ultracold atom interferometry in space
Bose-Einstein condensates (BECs) in free fall constitute a promising source for space-borne interferometry. Indeed, BECs enjoy a slowly expanding wave function, display a large spatial coherence and can be engineered and probed by optical techniques. Here we explore matter-wave fringes of multiple spinor components of a BEC released in free fall employing light-pulses to drive Bragg processes and induce phase imprinting on a sounding rocket. The prevailing microgravity played a crucial role in the observation of these interferences which not only reveal the spatial coherence of the condensates but also allow us to measure differential forces. Our work marks the beginning of matter-wave interferometry in space with future applications in fundamental physics, navigation and earth observation
Space-borne Bose-Einstein condensation for precision interferometry
Space offers virtually unlimited free-fall in gravity. Bose-Einstein
condensation (BEC) enables ineffable low kinetic energies corresponding to
pico- or even femtokelvins. The combination of both features makes atom
interferometers with unprecedented sensitivity for inertial forces possible and
opens a new era for quantum gas experiments. On January 23, 2017, we created
Bose-Einstein condensates in space on the sounding rocket mission MAIUS-1 and
conducted 110 experiments central to matter-wave interferometry. In particular,
we have explored laser cooling and trapping in the presence of large
accelerations as experienced during launch, and have studied the evolution,
manipulation and interferometry employing Bragg scattering of BECs during the
six-minute space flight. In this letter, we focus on the phase transition and
the collective dynamics of BECs, whose impact is magnified by the extended
free-fall time. Our experiments demonstrate a high reproducibility of the
manipulation of BECs on the atom chip reflecting the exquisite control features
and the robustness of our experiment. These properties are crucial to novel
protocols for creating quantum matter with designed collective excitations at
the lowest kinetic energy scales close to femtokelvins.Comment: 6 pages, 4 figure
Supplement 1: Space-borne frequency comb metrology
supplemental document Originally published in Optica on 20 December 2016 (optica-3-12-1381
Space-borne BoseâEinstein condensation for precision interferometry
Owing to the low-gravity conditions in space, space-borne laboratories enable experiments with extended free-fall times. Because BoseâEinstein condensates have an extremely low expansion energy, space-borne atom interferometers based on BoseâEinstein condensation have the potential to have much greater sensitivity to inertial forces than do similar ground-based interferometers. On 23 January 2017, as part of the sounding-rocket mission MAIUS-1, we created BoseâEinstein condensates in space and conducted 110 experiments central to matter-wave interferometry, including laser cooling and trapping of atoms in the presence of the large accelerations experienced during launch. Here we report on experiments conducted during the six minutes of in-space flight in which we studied the phase transition from a thermal ensemble to a BoseâEinstein condensate and the collective dynamics of the resulting condensate. Our results provide insights into conducting cold-atom experiments in space, such as precision interferometry, and pave the way to miniaturizing cold-atom and photon-based quantum information concepts for satellite-based implementation. In addition, space-borne BoseâEinstein condensation opens up the possibility of quantum gas experiments in low-gravity conditions1,2
Space-borne Bose-Einstein condensation for precision interferometry
Owing to the low-gravity conditions in space, space-borne laboratories enable experiments with extended free-fall times. Because BoseâEinstein condensates have an extremely low expansion energy, space-borne atom interferometers based on BoseâEinstein condensation have the potential to have much greater sensitivity to inertial forces than do similar ground-based interferometers. On 23 January 2017, as part of the sounding-rocket mission MAIUS-1, we created BoseâEinstein condensates in space and conducted 110 experiments central to matter-wave interferometry, including laser cooling and trapping of atoms in the presence of the large accelerations experienced during launch. Here we report on experiments conducted during the six minutes of in-space flight in which we studied the phase transition from a thermal ensemble to a BoseâEinstein condensate and the collective dynamics of the resulting condensate. Our results provide insights into conducting cold-atom experiments in space, such as precision interferometry, and pave the way to miniaturizing cold-atom and photon-based quantum information concepts for satellite-based implementation. In addition, space-borne BoseâEinstein condensation opens up the possibility of quantum gas experiments in low-gravity conditions