Standard and non-standard metarefraction with confocal lenslet arrays

A recent paper demonstrated that two lenslet arrays with focal lengths f_1 and f_2, separated by f_1 + f_2, change the direction of transmitted light rays approximately like the interface between isotropic media with refractive indices n_1 and n_2, where n_1 / n_2 = - f_1 / f_2 [J. Courtial, New J. Phys. 10, 083033 (2008)]. This is true if light passes through corresponding lenslets, that is lenslets that share an optical axis. Light can also pass through different combinations of non-corresponding lenslets. Such light can be either absorbed or allowed to form "ghost images"; either way, it leads to a limitation of the field of view of confocal lenslet arrays. This paper describes, qualitatively and quantitatively, a number of such field-of-view limitations.Comment: 10 pages, 8 figure

Imaging with parallel ray-rotation sheets

A ray-rotation sheet consists of miniaturized optical components that function - ray optically - as a homogeneous medium that rotates the local direction of transmitted light rays around the sheet normal by an arbitrary angle [A. C. Hamilton et al., arXiv:0809.2646 (2008)]. Here we show that two or more parallel ray-rotation sheets perform imaging between two planes. The image is unscaled and un-rotated. No other planes are imaged. When seen through parallel ray-rotation sheets, planes that are not imaged appear rotated, whereby the rotation angle changes with the ratio between the observer's and the object plane's distance from the sheets.Comment: 8 pages, 6 figure

Resistance and pathogenicity: how toxins are involved in the carrot-Alternaria dauci interaction

Leaf blight caused by Alternaria dauci is the most damaging foliar disease on carrots, impeding the mechanic harvest. Fungicides remain the most effective way to control this disease. However, those molecules are expensive, affect environment and could be insufficient. Only partially resistant cultivars are known and marketed but their resistance levels are not sufficient yet, and plant quantitative pathogen resistance mechanisms are poorly characterized. We chose to investigate such mechanisms in the Alternaria dauci – carrot interaction. Previously, several converging experimental results were obtained, showing that fungal toxins take a central place in this interaction (1). toxicity tests performed on carrot cells revealed that only the organic phase of A.dauci exudates is toxic (1). Moreover, a correlation between carrot plant resistance to A. dauci and carrot cells resistance to fungal exudates was found. These results incited us to identify and characterize A.dauci toxin(s) involved in pathogenicity, to decipher their biosynthesis pathway(s) and their regulations. Using HPLC profiles of organic phase exudates from different fungal strains, we uncovered a great variation in toxins production between fungal strains. Furthermore, a new correlation, between aggressiveness of these stains and some fungal exudate’s molecules quantities was found, suggesting that toxins production plays a major role in the A.dauci – carrot interaction. We performed extraction and purification of one of the candidate molecules. A toxicity test of this molecule has been achieved with a new protocol of survival quantification. The next step in this project will be the definition of the chemical structure of the candidate molecule and the elucidation of its biosynthesis pathway. To this end, the A.dauci transcriptome data will be used to select genes possibly involved in its biosynthesis pathway

The slowly variable star FY Lacertae

Photometric observations and analysis of FY Lac were performed in order to determine the variability characteristics, using measurements taken at Loiano site of Bologna Astronomical Observatory and AAVSO data. The star shows a Long Term variability with a preliminary period of about 274 +/- 28 days and photometric characteristics compatible with a red M5 III giant star, with a temperature of 3420 K degrees.Comment: 9 page

Discovering Rehabilitation trends in Spain: A bibliometric analysis

The main purpose of this study is to offer an overview of the rehabilitation research area in Spain from 1970 to 2018 through a bibliometric analysis. Analysis of performance and a co-word science mapping analysis were conducted to highlight the topics covered. The software tool SciMAT was used to analyse the themes concerning their performance and impact measures. A total of 3,564 documents from the Web of Science were retrieved. Univ Deusto, Univ Rey Juan Carlos and Basque Foundation for Science are the institutions with highest relative priority. The most important research themes are IntellectualDisability, Neck-Pain and Pain

Science mapping with asymmetrical paradigmatic proximity

We propose a series of methods to represent the evolution of a field of science at different levels: namely micro, meso and macro levels. We use a previously introduced asymmetric measure of paradigmatic proximity between terms that enable us to extract structure from a large publications database. We apply our set of methods on a case study from the Complex Systems Community through the mapping of more than 400 Complex Systems Science concepts indexed from a database as large as several millions of journal papers. We will first recapitulate the main properties of our asymmetric proximity measure. Then we show how salient paradigmatic fields can be embedded into a 2-dimensional visualization into which the terms are plotted according to their relative specificity and generality index. This meso-level helps us producing macroscopic maps of the field of science studied featuring the former paradigmatic fields