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Coronagraphic imaging of three weak-line T Tauri stars: evidence of planetary formation around PDS 70

Riaud, P.; Mawet, D.; Absil, O.; Boccaletti, A.; Baudoz, P.; Herwats, E.; Surdej, J.
Fonte: EDP Sciences Publicador: EDP Sciences
Tipo: Article; PeerReviewed Formato: application/pdf
Publicado em 04/10/2006 Português
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Context.High angular resolution imaging of nearby pre-main sequence stars with ages between 1 and 30 Myr can give valuable information on planet formation mechanisms. This range of ages is thought to correspond to the dissipation of the optically thick dust disks surrounding young stars and to the end of the planet formation. Aims.This paper presents new observations of three weak-line T Tauri Stars (WTTS) of intermediate ages ranging from 7 to 16 Myr. It aims at increasing the knowledge and sample of circumstellar disks around "old" WTTS. Methods.We observed three stars with the VLT's NAOS-CONICA adaptive optics system in coronagraphic mode. The four-quadrant phase mask coronagraph was used to improve the dynamic range (by a factor of ~100) while preserving the high angular resolution (inner working angle of 0".15). Results.One object of our sample (PDS 70), a K5 star, exhibits a brown dwarf companion and a disk in scattered light with a surface brightness power law of r^-2.8, extending from a distance of 14 to 140 AU (assuming a stellar distance of 140 pc) and an integrated luminosity of 16.7 mJy in the K_s-band. The mass of the companion can be estimated to be within a range between 27 and 50 Jupiter masses with an effective temperature of 2750 ± 100K. This object also shows a resolved outflow stretching up to ~550 AU. Conclusions.This newly detected circumstellar disk shows strong similarities with the disk around TW Hya...

Reporter; RIT Reporter; Reporter Magazine

Singh, G.; Cayley, M.; Blaustein, Hank
Fonte: Rochester Institute of Technology Publicador: Rochester Institute of Technology
Tipo: Magazine
Português
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Deans' List Announced; 15 Students Get 4.0 (p. 1); SC Proposes Changes in Publications (p. 1); PUP Wins Approval to Join Alpha Xi Delta National (p. 1); RAA Programs to Highlight National Brotherhood Week (p. 1); Delta Omicron's Ugly Man' Contest Launched Tonight (p. 1); Editorials: SC Retreat: For Fun or Profit (p. 2); The Life You Save ... (p. 2); Spatial Relationships Defined (p. 2); Indian Student Speaks Out Concerning The Sikh Religion and India's History (p. 2); Cayley's Corner (p. 2); Letters to the Editor ... (p. 2); 'Choraliers' Reactivated; Spring Concert Planned (p. 3); Summer Session Plans Announced (p. 3); 'Gazette' Continues Publication With Rejuvenated Editorial Staff (p. 3); Job Directory For Students (p. 3); Lecture Series Concluded Feb. 19 (p. 3); Art Exhibited (p. 3); The Charlotte Photographers (p. 4); Evening College Seeks Interest In Student Council (p. 6); Insurance Course Starts in March (p. 6); Three Day Seminar Held On Electronic Chatter (p. 6); Brennan Serves Evening Students (p. 6); Activity Calendar Announced (p. 6); Help Wanted! (p. 6); Woman's Column Coming Next Week In 'Reporter' (p. 6); Six Home Meets For Tiger Teams (p. 7); Lamoureux Sets Four Records; But Hoopsters Lose Again (p. 7); Tiger Tracks (p. 7); Frosh Tigers Down Fredonia (p. 7); Fencers Win Fifth; Remain Undefeated (p. 7); Miss Helms Named New TTS Operator (p. 7); Wrestlers Defeated By Lockhaven Team (p. 7); Phi Sig Tops IFC Bowling; Theta Xi...

Exploring evidence for X-ray generation mechanisms in T Tauri stars

Shukla, S.; Weintraub, D.; Kastner, Joel
Fonte: American Astronomical Society Publicador: American Astronomical Society
Tipo: Abstract
Português
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Pre main sequence stars emit X-rays, indicative of the presence of strong magnetic fields. The production of strong X-rays is thought to be related to magnetic reconnection events (MREs). The stimuli of the MREs that generate the X-rays, however, is still a subject of considerable debate. Is the stimulus dynamo activity (fast rotation) or accretion (star-disk interactions)? If PMS stars are like MS stars, fast rotation generates coronal X-rays; however, evidence exists that X-rays from some classical T Tauri stars (cTTS) may be generated through disk-star MREs and/or shocks associated with accretion. To test these hypotheses, we are undertaking a program of Chandra observations of coeval binary TTS systems. Using Chandra's Advanced CCD Imaging Spectrometer, we have observed V710 Tau, a binary system consisting of one cTTS, V710 Tau N, and one weak-lined T Tauri star (wTTS), V710 Tau S. The CXO/ACIS-S3 images, obtained in a 10 ks exposure on 29 December 2004, cleanly resolve the V710 Tau binary, and demonstrate that both stars emit X-rays. Preliminary results indicate that harder and more numerous X-rays are emitted from the cTTS than from the wTTS component. Since both stars appear nearly constant in count rate, neither the V710 Tau N/V710 Tau S X-ray flux ratio nor hardness ratio appears to be influenced by flaring. These data for this coeval binary contradict expectations that wTTS are more X-ray luminous than cTTS and that the star with the greater overall luminosity (in this case V710 Tau S) is more X-ray luminous. If the principle difference between the cTTS and the wTTS is the presence of active accretion in the cTTS...

Analgesia multimodal para el postoperatorio en la enfermedad renal crónica: fentanilo transcutáneo, fentanilo oral transmucosa y metamizol

Mesa Suárez,P.; Aceña Fabián,V.; González Forte,M.J.; Neira Reina,F.; Portilla Huerta,D.
Fonte: Revista de la Sociedad Española del Dolor Publicador: Revista de la Sociedad Española del Dolor
Tipo: info:eu-repo/semantics/article; journal article; info:eu-repo/semantics/publishedVersion Formato: text/html; application/pdf
Publicado em 01/04/2015 Português
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La enfermedad renal crónica (ERC) es una situación clínica cada vez más prevalente. Esto se debe en gran medida al aumento de la esperanza de vida y al incremento de la incidencia de la diabetes mellitus (DM) y la hipertensión arterial (HTA). Estos pacientes requieren un manejo cuidadoso de la analgesia postoperatoria. El fentanilo es un fármaco cuya farmacocinética encaja en el manejo del dolor en la ERC. Sus diferentes presentaciones comerciales permiten elaborar estrategias adecuadas para brindarles una analgesia postoperatoria de gran calidad. Presentamos el esquema de analgesia postoperatoria de un paciente en fallo renal severo sometido a artroplastia de cadera: metamizol (6 gramos/24 horas) en perfusión durante 48 horas, fentanilo transcutáneo TTS 25 microgramos/hora durante 48 horas y fentanilo oral transmucosa 200 microgramos en caso de exacerbación del dolor. Este tratamiento analgésico permitió el control satisfactorio del dolor sin que se presentaran vómitos, prurito ni estreñimiento; la calidad del sueño y el descanso nocturno fueron buenos.

Gabapentina en el tratamiento de la fibromialgia

Acín,M. P.; Escartín,R.
Fonte: Revista de la Sociedad Española del Dolor Publicador: Revista de la Sociedad Española del Dolor
Tipo: info:eu-repo/semantics/article; journal article; info:eu-repo/semantics/publishedVersion Formato: text/html; application/pdf
Publicado em 01/05/2005 Português
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Objetivos: La fibromialgia es una de las causas más comunes de dolor musculoesquelético crónico localizado o generalizado, que se caracteriza por la presencia de puntos anatómicos dolorosos, rigidez matutina, fatiga fácil, trastornos del sueño y otros síntomas asociados. Algunos autores lo relacionan con un procesamiento anormal del dolor a nivel central, considerando la fibromialgia como un dolor con componente neuropático. También se ha demostrado déficit en la secreción de serotonina y otras sustancias relacionadas con la regulación de los procesos dolorosos. En este trabajo valoramos la eficacia de gabapentina en pacientes diagnosticados de fibromialgia. Material y método: Estudiamos 24 pacientes, todas mujeres, edad media 42,54 ± 13,08 (33-60). El 50% (12) presentan cervicalgia y 50% (12) cervicalgia y lumbalgia como síntomas dolorosos principales. Estaban siendo tratadas con AINE 15 pacientes, tramadol 12, fentanilo TTS 2, ansiolíticos 9, antidepresivos 9, buprenorfina TDS 1, fisioterapia 14, inyección en puntos gatillo con anestésico local 13, iontoforesis 1. Estos tratamientos les habían proporcionado alguna mejoría, por lo que sin modificarlos se prescribe gabapentina como monoterapia anticonvulsivante. La intensidad del dolor se valora según EVA...

Síndroma de apneia obstrutiva do sono como causa de acidentes de viação

Aguiar,M; Valença,J; Felizardo,M; Caeiro,F; Moreira,S; Staats,R; Almeida,A A Bugalho de
Fonte: Sociedade Portuguesa de Pneumologia Publicador: Sociedade Portuguesa de Pneumologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/2009 Português
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Vários estudos demonstram que os doentes com síndroma de apneia obstrutiva do sono (SAOS) têm um risco aumentado de acidentes de viação. O objectivo do presente trabalho consistiu em analisar, nestes doentes, se há diferenças nos que referem acidentes e/ /ou quase acidentes e aqueles que o não fazem. Material e métodos: Estudaram-se prospectivamente 163 doentes com SAOS (índice apneia/hipopneia (IAH)>10/h) diagnosticados por polissonografia nocturna (PSG), todos condutores de veículos, 18,4% do quais profissionais. Na altura da entrevista clínica foi inquirido se tinham tido, nos três anos antes acidentes e/ou quase acidentes devido a hipersonia diurna (Grupo II = 74) ou não (Grupo I = 89). Estes dois grupos foram comparados quanto a: idade, índice de massa corporal (IMC), escala de sonolência de Epworth (ESE), PaO2 e PaCO2 diurnas, avaliação da qualidade de vida pelo inquérito Functional Outcomes of Sleep Questionnaire (FOSQ teste) e dados da polissonografia - tempo total de sono (TTS), eficiência do sono, estádios do sono, índice de microdespertares (IMD), índice de apneia/hipopneia (IAH), SaO2 mínima e média, % tempo SaO2<90% (T90), índice de dessaturação (IDS), tempo total em apneia/hipopneia (TTOT) (teste t de Student). Resultados: (Grupo I / Grupo II) idade (anos) - 57...