969 research outputs found

    First High-resolution Spectroscopic Observations of an Erupting Prominence Within a Coronal Mass Ejection by the Interface Region Imaging Spectrograph (IRIS)

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    Spectroscopic observations of prominence eruptions associated with coronal mass ejections (CMEs), although relatively rare, can provide valuable plasma and 3D geometry diagnostics. We report the first observations by the Interface Region Imaging Spectrograph (IRIS) mission of a spectacular fast CME/prominence eruption associated with an equivalent X1.6 flare on 2014 May 9. The maximum plane-of-sky and Doppler velocities of the eruption are 1200 and 460 km/s, respectively. There are two eruption components separated by ~200 km/s in Doppler velocity: a primary, bright component and a secondary, faint component, suggesting a hollow, rather than solid, cone-shaped distribution of material. The eruption involves a left-handed helical structure undergoing counter-clockwise (viewed top-down) unwinding motion. There is a temporal evolution from upward eruption to downward fallback with less-than-free-fall speeds and decreasing nonthermal line widths. We find a wide range of Mg II k/h line intensity ratios (less than ~2 expected for optically-thin thermal emission): the lowest ever-reported median value of 1.17 found in the fallback material and a comparably high value of 1.63 in nearby coronal rain and intermediate values of 1.53 and 1.41 in the two eruption components. The fallback material exhibits a strong (>5σ> 5 \sigma) linear correlation between the k/h ratio and the Doppler velocity as well as the line intensity. We demonstrate that Doppler dimming of scattered chromospheric emission by the erupted material can potentially explain such characteristics.Comment: 12 pages, 6 figures, accepted by ApJ (Feb 15, 2015

    Use of Supplements for Increasing Performances of Suckling Martinik Ewes When Fed Tropical Forages

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    Experiments have been carried out to determine the effects of supplementation upon milk production and growing performances with hair sheep Martinik ewes weighing 48 ± 4 kg liveweight (LW). In a first trial, 6 single bearing ewes (group GS) were offered individually a daily 0.5 kg of commercial pellets. They were compared to the control group (GN; 6 ewes) with no supplement during 10 weeks of lactation. Basal diet was chopped Digitaria decumbens grass ad libitum. In a second trial, level of supplementation was adapted to the ewes’ litter size: 6 twins bearing ewes (TW) and 6 single (SI). Mean milk production (oxytocin method) reached 1186 and 940 g.d-1 (P\u3c 0.05) for GS and GN ewes, respectively. Body condition score (BCS) of GS ewes maintained during lactation while those of GN ewes slightly decreased (P\u3c 0.05). No difference was recorded for lambs daily weight gain (DWG). Milk production varied significantly (P\u3c 0.05) according to the litter size: 926 and 1246 g.d-1 for SI and TW, respectively. The BCS of TW ewes decreased more than those of SI ewes (-1.4 vs –1.0). Individual DWG were different (P\u3c 0.01): 216 and 150 g.d-1 for single and twin lamb, respectively. It is concluded that use of supplements is necessary in intensive breeding conditions (high reproduction frequency and productivity), in order to allow high levels of performances when ewes are fed tropical forages

    Restoring testosterone levels by adding dehydroepiandrosterone to a drospirenone containing combined oral contraceptive: II Clinical effects

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    Objectives: Combined oral contraceptives (COCs) decrease androgen levels, including testosterone (T), which may be associated with sexual dysfunction and mood complaints in some women. We have shown that co-administration of dehydroepiandrosterone (DHEA) to a drospirenone (DRSP) containing COC restored total T levels to baseline and free T levels by 47%. Here we describe the effects on sexual function, mood and quality of life of such an intervention. Study design: This was a randomized, double-blind, placebo-controlled study in 99 healthy COC starters. A COC containing 30 μg ethinylestradiol (EE) and 3 mg DRSP was used for 3 cycles, followed by 6 cycles of the same COC combined with 50 mg/day DHEA or placebo. Subjects completed the Moos Menstrual Distress Questionnaire (MDQ), the McCoy Female Sexuality Questionnaire (MFSQ) and the short form of the Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q). Safety and tolerability, including effects on skin were evaluated. Results: The addition of DHEA induced small, but significant improvements compared to placebo in the MDQ score for: Autonomic reactions during the menstrual (- 2.0 vs 0.71; P = 0.05) and the pre-menstrual phase (- 3.1 vs 2.9; P = 0.01); and for Behavior during the inter-menstrual phase (- 1.4 vs 3.6; P = 0.02). A significant difference was found in the MDQ score for arousal during the pre-menstrual phase in favor of placebo (- 5.0 vs 1.0; P = 0.01). There were no statistically significant differences between groups for the MSFQ and Q-LES-Q scores. DHEA co-administration resulted in an acceptable safety profile. DHEA negated the beneficial effect of the COC on acne according to the subjects' self-assessment. Conclusions: Co-administration with DHEA did not result in consistent improvements in sexual function, mood and quality of life indicators in women taking EE/DRSP. Retrospectively, the 50 mg dose of DHEA may be too low for this COC. Implications: A well-balanced judgment of the clinical consequences of normalizing androgens during COC use may require complete normalization of free T

    Restoring testosterone levels by adding dehydroepiandrosterone to a drospirenone containing combined oral contraceptive: I Endocrine effects

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    Objectives: Combined oral contraceptives (COCs) decrease testosterone (T) levels. This study investigated restoration of T and other androgen concentrations during COC use by co-administration of dehydroepiandrosterone (DHEA). Study design: In this randomized, double-blind, placebo-controlled study in 99 new COC starters (18-35 years old with BMI range 18-34 kg/m2), a COC containing 30 μg ethinylestradiol (EE) and 3 mg drospirenone (DRSP) was used for 3 cycles, followed by 6 cycles of the same COC combined with either 50 mg/day DHEA or placebo. Total T, albumin, sex hormone-binding globulin (SHBG), DHEA-sulfate (DHEA-S), Δ4-androstenedione (AD), 3α-androstanediol glucuronide (ADG) and estradiol (E2) were measured, whereas free T and the free T index (FTI) were calculated. Assessments took place at baseline (no COC use), after the run-in period (COC use alone) and during the treatment period (DHEA or placebo). Results: During COC use alone androgen levels decreased, especially total T by 62% and free T by 86%, and SHBG increased by 243%. Total T increased with DHEA compared to placebo (change from end of run-in period to end of treatment period: 1.3 ± 1.2 nmol/L vs 0.0 ± 0.4 nmol/L; P < 0.0001), and was restored to baseline levels. Free T and the FTI increased significantly (P < 0.0001), but the free T level was still 53% below baseline levels. DHEA-S, AD and ADG increased significantly to levels above baseline (P < 0.0001 for each). DHEA had no effect on SHBG, albumin and E2. Conclusions: An EE/DRSP containing COC strongly suppressed endogenous androgen concentrations in all users. The addition of 50 mg DHEA to a COC regimen containing EE/DRSP restored total T to baseline levels, but free T levels were restored by only 47% as most of the T remains bound to SHBG. Implications: When using a COC that increases SHBG considerably, a daily dose of 50 mg DHEA is insufficient to normalize free T levels completely

    First high-resolution spectroscopic observations of an erupting prominence within a coronal mass ejection by the Interface Region Imaging Spectrograph (IRIS)

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    Spectroscopic observations of prominence eruptions associated with coronal mass ejections (CMEs), although relatively rare, can provide valuable plasma and three-dimensional geometry diagnostics. We report the first observations by the Interface Region Imaging Spectrograph mission of a spectacular fast CME/prominence eruption associated with an equivalent X1.6 flare on 2014 May 9. The maximum plane-of-sky and Doppler velocities of the eruption are 1200 and 460 km s−1, respectively. There are two eruption components separated by ~200 km s−1 in Doppler velocity: a primary, bright component and a secondary, faint component, suggesting a hollow, rather than solid, cone-shaped distribution of material. The eruption involves a left-handed helical structure undergoing counterclockwise (viewed top-down) unwinding motion. There is a temporal evolution from upward eruption to downward fallback with less-than-free-fall speeds and decreasing nonthermal line widths. We find a wide range of Mg ii k/h line intensity ratios (less than ~2 expected for optically-thin thermal emission): the lowest ever reported median value of 1.17 found in the fallback material, a comparably high value of 1.63 in nearby coronal rain, and intermediate values of 1.53 and 1.41 in the two eruption components. The fallback material exhibits a strong (>5α ) linear correlation between the k/h ratio and the Doppler velocity as well as the line intensity. We demonstrate that Doppler dimming of scattered chromospheric emission by the erupted material can potentially explain such characteristics.Publisher PDFPeer reviewe

    Form and formalism in linguistics

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    "Form" and "formalism" are a pair of highly productive and polysemous terms that occupy a central place in much linguistic scholarship. Diverse notions of "form"  – embedded in biological, cognitive and aesthetic discourses – have been employed in accounts of language structure and relationship, while "formalism" harbours a family of senses referring to particular approaches to the study of language as well as representations of linguistic phenomena. This volume brings together a series of contributions from historians of science and philosophers of language that explore some of the key meanings and uses that these multifaceted terms and their derivatives have found in linguistics, and what these reveal about the mindset, temperament and daily practice of linguists, from the nineteenth century up to the present day

    Form and formalism in linguistics

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    "Form" and "formalism" are a pair of highly productive and polysemous terms that occupy a central place in much linguistic scholarship. Diverse notions of "form"  – embedded in biological, cognitive and aesthetic discourses – have been employed in accounts of language structure and relationship, while "formalism" harbours a family of senses referring to particular approaches to the study of language as well as representations of linguistic phenomena. This volume brings together a series of contributions from historians of science and philosophers of language that explore some of the key meanings and uses that these multifaceted terms and their derivatives have found in linguistics, and what these reveal about the mindset, temperament and daily practice of linguists, from the nineteenth century up to the present day

    Form and formalism in linguistics

    Get PDF
    "Form" and "formalism" are a pair of highly productive and polysemous terms that occupy a central place in much linguistic scholarship. Diverse notions of "form"  – embedded in biological, cognitive and aesthetic discourses – have been employed in accounts of language structure and relationship, while "formalism" harbours a family of senses referring to particular approaches to the study of language as well as representations of linguistic phenomena. This volume brings together a series of contributions from historians of science and philosophers of language that explore some of the key meanings and uses that these multifaceted terms and their derivatives have found in linguistics, and what these reveal about the mindset, temperament and daily practice of linguists, from the nineteenth century up to the present day

    Form and formalism in linguistics

    Get PDF
    "Form" and "formalism" are a pair of highly productive and polysemous terms that occupy a central place in much linguistic scholarship. Diverse notions of "form"  – embedded in biological, cognitive and aesthetic discourses – have been employed in accounts of language structure and relationship, while "formalism" harbours a family of senses referring to particular approaches to the study of language as well as representations of linguistic phenomena. This volume brings together a series of contributions from historians of science and philosophers of language that explore some of the key meanings and uses that these multifaceted terms and their derivatives have found in linguistics, and what these reveal about the mindset, temperament and daily practice of linguists, from the nineteenth century up to the present day
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