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Characterisation of exoplanets is key to understanding their formation, composition and potential for life. Nulling interferometry, combined with extreme adaptive optics, is among the most promising techniques to advance this goal. We present an integrated-optic nuller whose design is directly scalable to future science-ready interferometric nullers: the Guided-Light Interferometric Nulling Technology, deployed at the Subaru Telescope. It combines four beams and delivers spatial and spectral information. We demonstrate the capability of the instrument, achieving a null depth better than 10 -3 with a precision of 10 -4 for all baselines, in laboratory conditions with simulated seeing applied. On sky, the instrument delivered angular diameter measurements of stars that were 2.5 times smaller than the diffraction limit of the telescope. These successes pave the way for future design enhancements: scaling to more baselines, improved photonic component and handling low-order atmospheric aberration within the instrument, all of which will contribute to enhance sensitivity and precision.

Highest resolution imaging in astronomy is achieved by interferometry, connecting telescopes over increasingly longer distances and at successively shorter wavelengths. Here, we present the first diffraction-limited images in visual light, produced by an array of independent optical telescopes, connected electronically only, with no optical links between them. With an array of small telescopes, second-order optical coherence of the sources is measured through intensity interferometry over 180 baselines between pairs of telescopes, and two-dimensional images reconstructed. The technique aims at diffraction-limited optical aperture synthesis over kilometre-long baselines to reach resolutions showing details on stellar surfaces and perhaps even the silhouettes of transiting exoplanets. Intensity interferometry circumvents problems of atmospheric turbulence that constrain ordinary interferometry. Since the electronic signal can be copied, many baselines can be built up between dispersed telescopes, and over long distances. Using arrays of air Cherenkov telescopes, this should enable the optical equivalent of interferometric arrays currently operating at radio wavelengths.

Objective: To study communication disability in stroke patients with aphasia., Patients and Methods: Prospective, multicentric cohort study of patients with aphasia, consecutively included after a first stroke, and examined 1 year later at home. Assessment included a stroke severity scale, the Barthel Index, the boston diagnostic aphasia examination, a communication questionnaire, and the aphasia depression rating scale., Results: A total of 164 patients were included. Among the 100 survivors assessed at follow-up, 24% had severe aphasia, 12% moderate aphasia and 64% mild aphasia according to the Boston diagnostic aphasia examination severity score. Patients mainly reported difficulties in conversation with strangers and/or on abstract topics, using a phone, reading and writing administrative documents, dealing with money and outdoor communication activities. Communication was strongly related to aphasia severity. Age, gender, education level, residence status and type of stroke had no influence on communication activity. On multivariate analysis, severity of stroke and severity of aphasia on inclusion were found to account for 58% of variance and were independent predictors of the communication questionnaire score at follow-up., Conclusion: Documenting the most impaired communication skills may help to set priority goals for speech and language therapy in aphasia.