TARANIS — Scientific payload and mission strategy

International audienceOn December 2010 the implementation phase of the TARANIS micro-satellite was authorized by the French space agency. TARANIS is dedicated to the study of impulsive transfers of energy between the Earth atmosphere and the space environment, and more precisely to the physics of the Transient Luminous Events (TLEs) and of the Terrestrial Gamma ray Flashes (TGFs). By 2015 TARANIS will provide combined Nadir observations of TLEs and TGFs, high resolution measurements of energetic electrons, and wave field measurements. The strategy adopted to maximize the scientific return of the data is presented

Should diastolic and systolic blood pressure be considered for cardiovascular risk evaluation: a study in middle-aged men and women

AbstractOBJECTIVESThe goal of this study was to evaluate the role of diastolic blood pressure (DBP) in cardiovascular mortality for different systolic blood pressure (SBP) levels in middle-aged men and women.BACKGROUNDIn middle-aged subjects it is unclear whether DBP, in addition to SBP, should be considered for risk evaluation.METHODSSubjects (77,023 men; 48,480 women) aged 40 to 70 years old, had no major cardiovascular disease, no antihypertensive treatment and were examined at the Centre d’Investigations Préventives et Cliniques between 1972 and 1988. Mortality was assessed for an 8- to 12-year period.RESULTSIn both genders, cardiovascular mortality increased with the SBP level. In men and women with normal SBP levels, DBP did not influence cardiovascular mortality after adjustment for age and SBP. In men with systolic hypertension, a U-shaped curve relationship between cardiovascular mortality and DBP was observed, with the lowest mortality rates in the group with DBP 90 to 99 mm Hg. Compared with this group, age- and SBP-adjusted cardiovascular mortality was higher by 73% (p < 0.02) in the group with DBP <90 mm Hg and by 65% (p < 0.001) in the group with DBP ≥110 mm Hg. In women with systolic hypertension, however, DBP was positively correlated with cardiovascular mortality.CONCLUSIONSIn middle-aged subjects, classification of cardiovascular risk according to DBP levels should take into account gender, especially when SBP levels are elevated. Men with systolic hypertension are at higher risk when their DBP is “normal” than when they present a mild to moderate increase in DBP. In women of the same age, however, systolic-diastolic hypertension represents a higher risk than isolated systolic hypertension

Temporary coronary artery occlusion during off-pump coronary artery bypass grafting with the new poloxamer P407 does not cause endothelial dysfunction in epicardial coronary arteries

ObjectiveThe aim of this study was to assess the efficacy of the novel reversible thermosensitive gel poloxamer 407 for occlusion of the coronary vessel necessary for minimally invasive operations and its effects on coronary endothelium.MethodsDomestic swine were submitted to occlusion of the left anterior descending or right coronary artery using the poloxamer. The left and right internal thoracic arteries were used as grafts to perform coronary artery bypasses. Animals were humanely killed after 3 hours of perfusion (acute; n = 8) or 3 days (subacute; n = 6). The vascular reactivity of coronary artery was evaluated in response to serotonin and bradykinin. Histologic studies were performed to analyze cardiomyocyte necrosis and endothelial coverage.ResultsThe gel led to an occlusion of 7.8 ± 2.2 minutes. Concentration-response curves of occluded coronary segments showed no difference of endothelium-dependent relaxations in both operated groups (P < .05 vs control). Histologic studies demonstrated the absence of cardiomyocyte necrosis after coronary artery occlusion in the acute group; a small infarct zone was detected in 1 animal in the subacute group, resulting from an occlusion of the first diagonal branch. The endothelial layer coverage was preserved in both groups.ConclusionThe poloxamer 407 represents a promising technique for obtaining hemostasis at the site of anastomosis during construction of bypasses during beating heart coronary artery surgery, without damage to the endothelium or ischemic consequence

Anemia, iron status, and associated protective and risk factors among children and adolescents aged 3 to 19 years old from four First Nations communities in Quebec

Objectives: Anemia and iron deficiency (ID) are frequent among Indigenous children of Canada, but few data are available in Quebec. The present study aimed to characterize anemia and ID prevalence and associated protective and risk factors among First Nations youth in Quebec. Methods: The 2015 First Nations (JES!-YEH!) pilot study was conducted among children and adolescents (3 to 19 years; n=198) from four First Nations communities in Quebec. Blood and urine samples and anthropometric measurements were collected. Hemoglobin (Hb), serum ferritin (SF), plasma hs-CRP, and urinary cotinine levels were measured. Factors associated with anemia and ID (including traditional and market food consumption) were assessed using an interview-administered food frequency questionnaire, based on which nutritional intakes were calculated. Structural equation models were used totest associations. Results: The prevalence of anemia and ID was elevated (16.8% and 20.5% respectively). Traditional meat, fruit, and fruit juice (naturaland powdered)—via their positive association with vitamin C intake—were the only food variables positively associated with SF (coefficient [95% CI] 0.017 [0.000, 0.114]; 0.090 [0.027, 0.161]; and 0.237 [0.060, 0.411]). Male sex was also associated with higher SF (0.295 [0.093, 0.502]). Inflammation status (hs-CRP > 5 mg/L) was inversely associated with Hb (−0.015 [−0.025,−0.005]), whereas SF was positively associated with Hb (0.066 [0.040, 0.096]). Fruit and juice consumption was also positively associated with Hb, via vitamin C intake and SF (0.004 [0.001, 0.010]; 0.008 [0.003, 0.017]). Conclusions: Interventions fostering healthier food environments as well as higher consumption of traditional meats and foods naturally rich in vitamin C, which is known to enhance iron absorption, and fighting inflammation could contribute to decrease the high prevalence of anemia and ID in this young Indigenous population.Objectifs : L’anémie et la carence en fer sont fréquentes chez les enfants autochtones au Canada, mais peu de données sont disponibles au Québec. La présente étude visait à caractériser la prévalence de l’anémie et de la carence en fer et les facteurs protecteurs et des risques associés chez des jeunes des Premières Nations du Québec. Méthodes : En 2015, l’étude pilote Jeunes Environnement et Santé (JES! - YEH!) a été menée chez des enfants et des adolescents (3 à 19 ans,n= 198) de quatre communautés de Premières Nations au Québec. Des échantillons de sang et d’urine et des mesures anthropométriques ont été recueillis. Les concentrations d’hémoglobine, de ferritine sérique, de hs-CRP plasmatique et decotinine urinaire ont été mesurées. Les facteurs associés à l’anémie et à la carence en fer (y compris la consommation d’aliments traditionnels et de marché) ont été évalués à l’aide de questionnaires de fréquences alimentaires administré par un assistant de recherche, à partir desquels les apports nutritionnels ont été calculés. Des modèles d’équations structurelles ont été utilisés pour tester les associations. Résultats : La prévalence de l’anémie et de la carence en fer était élevée (16,8 % et 20,5 % respectivement). La viande traditionnelle, les fruits et les jus de fruits (naturels et en poudre) − par l’intermédiaire de leur association positive avec l’apport en vitamine C − étaient les seules variables alimentaires positivement associées à la ferritine sérique (coefficient [IC à 95 %] : 0,017 [0,000, 0,114]; 0,090 [0,027, 0,161]; et 0,237 [0,060, 0,411]). Le sexe masculin était également associé à une ferritine sérique plus élevée (0,295 [0,093, 0,502]). Le statut inflammatoire (hs-CRP > 5 mg/L) était inversement associé à l’hémoglobine (−0,015 [−0,025,−0,005]) alors que la ferritine sérique était positivement associée à l’hémoglobine (0,066 [0,040, 0,096]). La consommation de fruits et de jus était aussi positivement associée à l’hémoglobine via l’apport en vitamine C et la ferritine sérique (0,004 [0,001, 0,010]; 0,008 [0,003, 0,017]). Conclusions : Les interventions favorisant des environnements alimentaires plus sains ainsi qu’une consommation plus élevée de viandes et d’aliments traditionnels naturellement riches en vitamine C, qui sont connus d’améliorer l’absorption de fer, ainsi que luttant contre l’inflammation pourraient contribuer à diminuer la prévalence élevée d’anémie et de la carence en fer dans cette jeune population autochtone

Bit-Error-Rate Assessment of 170-Gb/s Regeneration Using a Saturable Absorber and a Nonlinear-Fiber-Based Power Limiter

International audienceA 170-Gb/s all-optical 2R regenerator made up of a fast saturable absorber and a highly nonlinear-fiber-based power limiter is reported for the first time. Bit-error-rate assessment of one of the four 42.5-Gb/s optical time-division-multiplexed tributaries shows a receiver sensitivity improvement

Spatial and temporal evolution of Liassic to Paleocene arc activity in southern Peru unraveled by zircon U-Pb and Hf in-situ data on plutonic rocks

International audienceCordilleran-type batholiths are built by prolonged arc activity along active continental margins and provide detailed magmatic records of the subduction system evolution. They complement the stratigraphic record from the associated forearcs and backarcs. We performed in-situ U-Pb geochronology and Hf isotope measurements on zircon grains from a large set of plutonic rocks from the Coastal Batholith in southern Peru. This batholith emplaced into the Precambrian basement and the Mesozoic sedimentary cover. We identify two major periods of voluminous arc activity, during the Jurassic (200-175 Ma) and the Late Cretaceous-Paleocene (90-60 Ma). Jurassic arc magmatism mainly resulted in the emplacement of a dominantly mafic suite with εHf values ranging from − 9.5 to + 0.1. Published ages south of the Arequipa area suggest that the arc migrated southwestward out of the study area during the Middle Jurassic. After a magmatic gap of 85 Ma, arc activity abruptly resumed 90 Ma ago in Arequipa. Intrusive bodies emplaced into both basement and older Jurassic intrusions and strata. This activity culminated between 70 and 60 Ma with the emplacement of very large volumes of dominantly quartz-dioritic magmas. This last episode may be considered as a flare-up event, characterized by intense magmatic transfers into the crust and rapid relief creation. The Late Cretaceous-Paleocene initial εHf are shifted toward positive values (up to + 3.3 and + 2.6) compared to the Jurassic ones, indicating either a larger input of juvenile magmas, a lesser interaction with the ancient crust, or an increase of re-melting of young mantle-derived mafic lower crust. These magmatic fluxes with juvenile component are coeval with the onset of the crustal thickening at 90 Ma and represent a significant contribution to the formation of the continental crust in this area

Incarceration history and risk of HIV and hepatitis C virus acquisition among people who inject drugs: a systematic review and meta-analysis

Background People who inject drugs (PWID) experience a high prevalence of incarceration and might be at high risk of HIV and hepatitis C virus (HCV) infection during or after incarceration. We aimed to assess whether incarceration history elevates HIV or HCV acquisition risk among PWID. Methods In this systematic review and meta-analysis, we searched MEDLINE, Embase, and PsycINFO databases for studies in any language published from Jan 1, 2000 until June 13, 2017 assessing HIV or HCV incidence among PWID. We included studies that measured HIV or HCV incidence among community-recruited PWID. We included only studies reporting original results and excluded studies that evaluated incident infections by self-report. We contacted authors of cohort studies that met the inclusion or exclusion criteria, but that did not report on the outcomes of interest, to request data. We extracted and pooled data from the included studies using random-effects meta-analyses to quantify the associations between recent (past 3, 6, or 12 months or since last follow-up) or past incarceration and HIV or HCV acquisition (primary infection or reinfection) risk among PWID. We assessed the risk of bias of included studies using the Newcastle-Ottawa Scale. Between-study heterogeneity was evaluated using the I2 statistic and the P-value for heterogeneity. Findings We included published results from 20 studies and unpublished results from 21 studies. These studies originated from Australasia, western and eastern Europe, North and Latin America, and east and southeast Asia. Recent incarceration was associated with an 81% (relative risk [RR] 1·81, 95% CI 1·40–2·34) increase in HIV acquisition risk, with moderate heterogeneity between studies (I2=63·5%; p=0·001), and a 62% (RR 1·62, 95% CI 1·28–2·05) increase in HCV acquisition risk, also with moderate heterogeneity between studies (I2=57·3%; p=0·002). Past incarceration was associated with a 25% increase in HIV (RR 1·25, 95% CI 0·94–1·65) and a 21% increase in HCV (1·21, 1·02–1·43) acquisition risk. Interpretation Incarceration is associated with substantial short-term increases in HIV and HCV acquisition risk among PWID and could be a significant driver of HCV and HIV transmission among PWID. These findings support the need for developing novel interventions to minimise the risk of HCV and HIV acquisition, including addressing structural risks associated with drug laws and excessive incarceration of PWID