The design of the n2EDM experiment: nEDM Collaboration.

We present the design of a next-generation experiment, n2EDM, currently under construction at the ultracold neutron source at the Paul Scherrer Institute (PSI) with the aim of carrying out a high-precision search for an electric dipole moment of the neutron. The project builds on experience gained with the previous apparatus operated at PSI until 2017, and is expected to deliver an order of magnitude better sensitivity with provision for further substantial improvements. An overview is of the experimental method and setup is given, the sensitivity requirements for the apparatus are derived, and its technical design is described.

[Multifocal ERG using ERG-jet and Gold Foil electrodes in normal subjects: comparison and reproducibility]. / ERG multifocal avec électrodes ERG-jet et Gold Foil chez le sujet normal: comparaison et reproductibilité.

PURPOSE: To compare multifocal electroretinogram (mfERG) amplitudes with the Gold Foil electrode and ERG-jet electrode. To study mfERG amplitude changes between two successive records (intraindividual reproducibility). METHODS: The right eye of 27 normal subjects was examined. Two mfERG recordings using the 61-hexagon strategy (Vision Monitor, Métrovision, France) were made with both ERG-jet and Gold Foil electrodes. N1 and P1 wave amplitudes were analyzed in the central response and in four concentric rings. Bland and Altman analysis was used for the reproducibility study. RESULTS: MfERG amplitudes were significantly lower with the Gold Foil electrode, which averaged 72+/-10% of ERG-jet amplitudes. For N1 and P1 waves, the percentage change for the intraindividual reproducibility study was 9.1% and 6.7%, respectively, with the ERG-jet electrode and 18.2% and 13.5%, respectively, with the Gold Foil electrode. CONCLUSION: MfERG amplitudes were larger and more reproducible with an ERG-jet electrode than with a Gold Foil electrode. The limits of agreement of each ring can be used in clinical practice to determine whether the variation between two mfERG recordings over time is normal, which could reflect a retinal disorder.

The effects of spatial frequency on binocular fusion: from elementary to complex images.

Factors limiting binocular fusion were studied using 2-dimensional difference of Gaussian (2D-DOG) stimuli. The proportion of fused stimuli and observer's response time were determined for stimuli that varied in spatial frequency composition between 0.22 and 4.8 cycles per degree. At small disparities, mean fusion response times were short and relatively stable but increased rapidly once the disparity reached a certain critical value. This 2-phase function implies the existence of 2 separate fusional mechanisms: a rapid neurally based fusional process, which operates at small disparities, and a second mechanism involving reflexive vergence movements operating at disparities 2 to 3 times larger. Both mechanisms are highly influenced by spatial frequency, being 4 to 5 times more effective at low spatial frequencies. Additional experiments demonstrated that with compound stimuli, the fusion limit is not determined by the highest spatial frequency components (as had been reported previously) but, rather, can take advantage of the additional fusional range associated with low spatial frequencies. Such cooperation may be obvious only in the case of 2-dimensional stimuli.

[Personnel with poor vision at fighter pilot school]. / Des malvoyants à l'école des pilotes de chasse.

The piloting of fighting aircraft, the navigation of space-shuttle, the piloting of an helicopter in tactical flight at an altitude of 50 metres require the use of all sensorial, ocular, vestibular, proprioceptive ... sensors. So, the selection and the follow-up of these aerial engines' pilots need a very complete study of medical parameters, in particular sensorial and notably visual system. The doctors and the expert researchers in Aeronautical and spatial Medicine of the Army Health Department, which have in charge the medical supervision of flight crew, should study, create, and improve tests of visual sensorial exploration developed from fundamental and applied research. These authenticated tests with military pilots were applied in ophthalmology for the estimation of normal and deficient vision. A proposition to change norms of World Health Organisation applied to the vision has been following these to low visual persons was equally introduced.

Effects of a vigilance-enhancing drug, modafinil, on rat brain metabolism: a 2D COSY 1H-NMR study.

The effects of modafinil, a vigilance-enhancing drug, on brain metabolism were investigated directly in situ by the 2D COSY 1H-NMR spectroscopy in anesthetized rats. Modafinil (600 mg/kg, i.p.) induced significant increases in both aspartate (72% +/- 15%) and glutamate-glutamine pool (28% +/- 8%) simultaneously with increases in inositol (51% +/- 19%) and creatine-phosphocreatine pool (47% +/- 14%) in comparison with control values (P < 0.05; n = 5). These results suggest that the awakening properties of modafinil could be mediated by metabolic activation.

[A new simple instrument for ophthalmologic evaluation of patients with "low vision"]. / Nouveau matériel simple pour l'évaluation par l'ophthalmologiste d'un patient atteint de "basse vision".

Authors present specially adapted visual acuity charts for "low vision" patients. For them refraction must be surveyed as often as possible.

[A new evaluation system of 3D vision]. / Nouveaux systèmes d'évaluation de la vision 3 D.

3D vision assessment depends on monocular and binocular factors. In ophthalmology, it is clinically evaluated through the optometric examination which is not exhaustive according to the monocular elements and doesn't take on the visual stimulus quantification. The video and electro-optic displays can meet all these exigencies. The basic principles they share are exposed and then an illustration is given of their performance and their adaptation to the physiologic mechanisms. So is presented a study on the fusion area of heterophoric subjects depending on the stimulus spatial frequencies (the synthetic precisely quantified images shown were circular DOGs). This area is greatly modified following the variety of subject's heterophoria.

[Contrast sensitivity function. Results of an epidemiologic study]. / De la valeur de la fonction de sensibilité au contraste. Résultats d'une étude épidémiologique.

The examination of contrast sensitive function partially tests the capabilities of ganglion cells. However, this method has not yet proven to be an unquestionable way of diagnosis, 108 Subjects with various pathological conditions were tested with this technique in order to confirm its value for ophthalmological pathology. The first epidemiological results show that there are changes in curves obtained for clinically sick patients, and that the currently used equipment is most sensitive of the 4 th frequency and high frequencies. Finally, each colored stimulation is very significant at low frequencies.

[Aids for low vision--strategic approach]. / Les aides à la basse vision--approche stratégique.

There are currently methods to rehabilitate the remaining visual function of visually impaired people. Treatment stages and tests are based on classical physiology of vision and still remain strictly experimental. Recent investigations showed that the visual system, as a whole, operates as a space frequency analyzer. There are reception to each spatial frequency. They have to be assessed with accuracy before any rehabilitation attempting to develop channels which are still functional by elective stimulation. This stimulation must have a maximum determined energetic efficiency. The study of the Fourier spectrum on two different images demonstrates this possibility and starts opening the way for specific research.

Head-up/head-down transition: measurement of transition times.

A method was developed to measure transition times between a head-up signal and a response given to a head-down display. Various arrangements of motor response (vocal, hand) and HDD images were used. In the first experiment, vocal and manual response times were recorded in a current fighter aircraft mock-up situation. The shortest times were obtained for voice responses. The time elapsed between a HUD signal and the simple response to the HDD was approximately 1600 ms. The time for physical transition where accommodation changes occur was 700 ms. In the second experiment, two types of images were displayed on the HDD: a "positive" contrast (green symbol on black background), and a "negative" contrast (black symbol on green background) in order to compare accommodation to structured and unstructured backgrounds. Perception time was significantly shorter for the "positive" contrast, and transition times were similar to those measured in the first experiment. This method permits the evaluation in a dynamic aeronautical environment of the acquisition and processing of information. Changes in psychological conditions (heavier information processing) and/or physiological conditions (changing accommodation, gaze axis, convergence) can be evaluated in future research.

[Clinical value of the colored contrast sensitivity test. Preliminary note]. / Intérêt clinique de l'examen de la sensibilité au contraste coloré. Note préliminaire.

Evaluation of color contrast sensitivity is a new test for the assessment of visual capacity and especially of light stimulation transfer along the optic pathway. The color technique yields more accurate results. It is combined with previously existing functional examinations and allows very early detection of subclinical signs of starting pathological processes.

Visual acuity in color contrast on cathode ray tubes: role of luminance, hue, and saturation contrasts.

Three experiments were conducted on 90 flying personnel to determine the role of luminance, hue, and saturation contrasts on angular visual acuity measured on a CRT system. A Snellen E test object was displayed under various visual acuity conditions on a TV screen, in color contrast, using red, yellow, green, cyan, blue, purple, white, and black. The response system gives response times and quality. The three photocolorimetric parameters are classified through data processing. All other things being equal, the best visual acuity is obtained under a luminance contrast. Two groups of colors can be differentiated under a hue contrast. The first group (red, blue, purple) is better perceived than the second (green, cyan, yellow, white) whatever the other color in simultaneous contrast may be. Higher saturation enhances visual acuity. A curve of mean response time vs. test object sizes is established for the various color couples. The obtained results are of interest for aerospace ergonomics.

Anaemia treatment trials in a rural population of Tanzania.

In a coastal population in whom anaemia was common, two randomised controlled trials were undertaken to investigate the effectiveness of treating iron deficiency anaemia at a dispensary and at primary schools. For anaemic adult villagers treated at a dispensary, one dose of tetrachlorethylene for hookworm infection and a once per week visit to collect medicines were found to be satisfactory. A small but significant increase in haemoglobin level was produced by four weeks oral iron therapy, but this was only maintained after seven months by the group that had initially also received tetrachlorethylene. In children (5-14 years) no significant rise in haemoglobin level was obtained by using oral iron and/or TCE, either at the dispensary or at the primary schools. This suggests that malaria was a more potent cause of anaemia in these children.