57 research outputs found
Anisotropic super-attenuation of capillary waves on driven glass interfaces
Metrological AFM measurements are performed on the silica glass interfaces of
photonic band-gap fibres and hollow capillaries. The freezing of attenuated
out-of-equilibrium capillary waves during the drawing process is shown to
result in a reduced surface roughness. The roughness attenuation with respect
to the expected thermodynamical limit is determined to vary with the drawing
stress following a power law. A striking anisotropic character of the height
correlation is observed: glass surfaces thus retain a structural record of the
direction of the flow to which the liquid was submitted
Nondestructive measurement of the roughness of the inner surface of hollow core-photonic bandgap fibers
We present optical and atomic force microscopy measurements of the roughness of the core wall surface within a hollow core photonic bandgap fiber (HC-PBGF) over the [3×10-2 µm-1 to 30 µm-1] spatial frequency range. A recently developed immersion optical profilometry technique with picometer-scale sensitivity was used to measure the roughness of air-glass surfaces inside the fiber at unprecedentedly low spatial frequencies, which are known to have the highest impact on HC-PBGF scattering loss and, thus, determine their loss limit. Optical access to the inner surface of the core was obtained by the selective filling of the cladding holes with index matching liquid using techniques borrowed from micro-fluidics. Both measurement techniques reveal ultralow roughness levels exhibiting a 1/f spectral power density dependency characteristic of frozen surface capillary waves over a broad spatial frequency range. However, a deviation from this behavior at low spatial frequencies was observed for the first time, to the best of our knowledge
AMBER : a near infrared focal instrument for the VLTI
10 pagesInternational audienceAMBER is the General User near-infrared focal instrument of the Very Large Telescope interferometer. Its specifications are based on three key programs on Young Stellar Objects, Active Galactic Nuclei central regions, masses and spectra of hot Extra Solar Planets. It has an imaging capacity because it combines up to three beams and very high accuracy measurement are expected from the spatial filtering of beams by single mode fibers and the comparison of measurements made simultaneously in different spectral channels
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Using a community-based definition of poverty for targeting poor households for premium subsidies in the context of a community health insurance in Burkina Faso
Background: One of the biggest challenges in subsidizing premiums of poor households for community health insurance is the identification and selection of these households. Generally, poverty assessments in developing countries are based on monetary terms. The household is regarded as poor if its income or consumption is lower than a predefined poverty cut-off. These measures fail to recognize the multi-dimensional character of poverty, ignoring community members? perception and understanding of poverty, leaving them voiceless and powerless in the identification process. Realizing this, the steering committee of Nouna's health insurance devised a method to involve community members to better define `perceived? poverty, using this as a key element for the poor selection. The community-identified poor were then used to effectively target premium subsidies for the insurance scheme.
Methods: The study was conducted in the Nouna's Health District located in northwest Burkina Faso. Participants in each village were selected to take part in focus-group discussions (FGD) organized in 41 villages and 7 sectors of Nouna's town to discuss criteria and perceptions of poverty. The discussions were audio recorded, transcribed and analyzed in French using the software NVivo 9.
Results: From the FGD on poverty and the subjective definitions and perceptions of the community members, we found that poverty was mainly seen as scarcity of basic needs, vulnerability, deprivation of capacities, powerlessness, voicelessness, indecent living conditions, and absence of social capital and community networks for support in times of need. Criteria and poverty groups as described by community members can be used to identify poor who can then be targeted for subsidies.
Conclusion: Policies targeting the poorest require the establishment of effective selection strategies. These policies are well-conditioned by proper identification of the poor people. Community perceptions and criteria of poverty are grounded in reality, to better appreciate the issue. It is crucial to take these perceptions into account in undertaking community development actions which target the poor. For most community-based health insurance schemes with limited financial resources, using a community-based definition of poverty in the targeting of the poorest might be a less costly alternative
Association of the PHACTR1/EDN1 genetic locus with spontaneous coronary artery dissection
Background:
Spontaneous coronary artery dissection (SCAD) is an increasingly recognized cause of acute coronary syndromes (ACS) afflicting predominantly younger to middle-aged women. Observational studies have reported a high prevalence of extracoronary vascular anomalies, especially fibromuscular dysplasia (FMD) and a low prevalence of coincidental cases of atherosclerosis. PHACTR1/EDN1 is a genetic risk locus for several vascular diseases, including FMD and coronary artery disease, with the putative causal noncoding variant at the rs9349379 locus acting as a potential enhancer for the endothelin-1 (EDN1) gene.
Objectives:
This study sought to test the association between the rs9349379 genotype and SCAD.
Methods:
Results from case control studies from France, United Kingdom, United States, and Australia were analyzed to test the association with SCAD risk, including age at first event, pregnancy-associated SCAD (P-SCAD), and recurrent SCAD.
Results:
The previously reported risk allele for FMD (rs9349379-A) was associated with a higher risk of SCAD in all studies. In a meta-analysis of 1,055 SCAD patients and 7,190 controls, the odds ratio (OR) was 1.67 (95% confidence interval [CI]: 1.50 to 1.86) per copy of rs9349379-A. In a subset of 491 SCAD patients, the OR estimate was found to be higher for the association with SCAD in patients without FMD (OR: 1.89; 95% CI: 1.53 to 2.33) than in SCAD cases with FMD (OR: 1.60; 95% CI: 1.28 to 1.99). There was no effect of genotype on age at first event, P-SCAD, or recurrence.
Conclusions:
The first genetic risk factor for SCAD was identified in the largest study conducted to date for this condition. This genetic link may contribute to the clinical overlap between SCAD and FMD
A simplified interventional mapping system (SIMS) for the selection of combinations of targeted treatments in non-small cell lung cancer
Non-small cell lung cancer (NSCLC) is a leading cause of death worldwide. Targeted monotherapies produce high regression rates, albeit for limited patient subgroups, who inevitably succumb. We present a novel strategy for identifying customized combinations of triplets of targeted agents, utilizing a simplified interventional mapping system (SIMS) that merges knowledge about existent drugs and their impact on the hallmarks of cancer. Based on interrogation of matched lung tumor and normal tissue using targeted genomic sequencing, copy number variation, transcriptomics, and miRNA expression, the activation status of 24 interventional nodes was elucidated. An algorithm was developed to create a scoring system that enables ranking of the activated interventional nodes for each patient. Based on the trends of co-activation at interventional points, combinations of drug triplets were defined in order to overcome resistance. This methodology will inform a prospective trial to be conducted by the WIN consortium, aiming to significantly impact survival in metastatic NSCLC and other malignancies
The creative voice: free indirect speech in the cinema of Rohmer and Bresson
This article examines a particular use of the voice in cinema which conveys character reflexivity and generates expressive ambiguity in a film's narrative point of view. Drawing on Pasolini's notion of the free indirect style and Deleuze's elaboration of this into his concept of the free indirect speech-act, two different creative uses of speech are analysed: one in Rohmer's Claire's Knee (1970) and the other in Bresson's Diary of a Country Priest (1951). The essay finds that when characters narrate their thoughts, feelings, actions or experiences in a reflexive manner (that is, to themselves, even if also to another), and this activity becomes for a time the primary event of the film, these characters step into the role of storyteller. They become both subject and object of their utterances which take on the style of the free indirect. With this, the voice enters into a new relationship with the image – directing, counterpointing, or disconnecting from it – changing the function of voice and image while seeming momentarily to supplant the film's narration. The symbolic nature of language gives words the power to create images and meaning that cannot be captured or conveyed by the camera alone. Privileging speech as a creative force not only dimensionalises character but, on a formal level, creates a role for voice that allows it to exist not as an appendage to the image but for its own sake. In order to suggest practical uses for these theoretical considerations, Bresson's and Rohmer's reflections on the role of the voice are also discussed
Mechanical and AFM investigations of elastomers filled with multiwall carbon nanotubes
International audienceStrong reinforcing effects are observed when multiwall carbon nanotubes are incorporated in a styrene-butadiene copolymer. The good level of dispersion of carbon nanotubes in the host matrix that allows to take advantage of their high aspect ratio as well as their orienting capability under uniaxial extension, appear to be the main parameters for mechanical reinforcement. Atomic force microscopy carried out in the unstretched and stretched states has been shown to bring important insights for the understanding of the mechanical properties of the composites
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