Ptychographic imaging with a compact gas-discharge plasma extreme ultraviolet light source

We report the demonstration of scanning-probe coherent diffractive imaging method (also known as ptychographic CDI) using a compact and partially-coherent gas-discharge plasma source of extreme ultraviolet (EUV) radiation at 17.3nm wavelength. Until now, CDI has been mainly carried out with coherent, high-brightness light sources, such as 3rd generation synchrotrons, X-ray free-electron lasers and high harmonic generation. Here we performed ptychographic lensless imaging of an extended sample using a compact, lab-scale source. The CDI reconstructions were achieved by applying constraint relaxation to the CDI algorithm. Experimental results indicate that our method can handle the low spatial coherence, broadband nature of the EUV illumination as well as the residual background due to visible light emitted by the gas-discharge source. The ability to conduct ptychographic imaging with lab-scale and partially coherent EUV sources is expected to significantly expand the applications of this powerful CDI method

CCL2/CCR2 and CX3CL1/CX3CR1 chemokine axes and their possible involvement in age-related macular degeneration

The causes of age-related macular degeneration (AMD) are not well understood. Due to demographic shifts in the industrialized world a growing number of people will develop AMD in the coming decades. To develop treatments it is essential to characterize the disease's pathogenic process. Over the past few years, numerous studies have focused on the role of chemotactic cytokines, also known as chemokines. Certain chemokines, such as CCL2 and CX3CL1, appear to be crucial in subretinal microglia and macrophage accumulation observed in AMD, and participate in the development of retinal degeneration as well as in choroidal neovascularization. This paper reviews the possible implications of CCL2 and CX3CL1 signaling in AMD. Expression patterns, single nucleotide polymorphisms (SNPs) association studies, chemokine and chemokine receptor knockout models are discussed. Future AMD treatments could target chemokines and/or their receptors

Thinning of the RPE and choroid associated with T lymphocyte recruitment in aged and light-challenged mice

International audienceThe choroidal vasculature is essential when it comes to bringing oxygen and nutrients to the functioning retina and evacuating debris resulting from the normal visual cycle. Choroidal thinning is a common feature in many human eye diseases, including high myopia [1,2] and retinitis pigmentosa [3,4], and has been reproducibly observed with age [5-7]. However, the association between choroidal thinning and age-related macular degeneration (AMD) remains controversial. Some authors have reported the loss of choriocapillaries in eyes with exudative AMD [8], and choroidal thinning has been detected in some studies [9-11]. Choroidal thinning has also been associated with geographic atrophy (GA), the dry form of late AMD [12-15]. A morphometric analysis by Ramrattan et al. more than two decades ago showed a decrease in choriocapillary density and diameter with age and in GA, but choroidal thinning was only significant with age [6]. Moreover, it has been reported that the choriocapillaries and choroid are thinner in areas where the RPE has degenerated [8]. However, all studies agree that aging is associated with significant choroidal thinning [16-18]. The exact mechanisms behind choroidal thinning with age or disease are not clear. The RPE is a monolayer of pigmented cells situated between photoreceptors and Bruch's membrane; its plays an essential role in the visual cycle. RPE65, which is also called 11-cis retinol isomerase and is strongly expressed in the RPE, participates in the production of 11-cis retinal [19], which is essential for photoreceptor function [20]. Mutations in the RPE65 gene cause progressive photoreceptor degeneration [21,22] and adult RPE65 −/

The Impact of Public Agricultural Spending on Foreign Direct Investment Inflows in Agriculture in South Africa: An ARDL Analysis

Since the transformation of South African agriculture post-apartheid, public agricultural spending and foreign direct investment in agriculture were regarded as predominantly essential for the development of agriculture sector. However, many authors still argue whether public agriculture spending should be complemented by foreign direct investment inflows in agriculture or vice versa.  Thus, the key focus of this paper is to investigate the impact of public agricultural spending on foreign direct investment inflows in agriculture in South Africa over the period 1991-2019. The Autoregressive distributed lag(ARDL) Bounds test and Granger causality were used to investigate both short run and long-run impact of public  agricultural spending on foreign direct investment inflows in agriculture. The results of the long run model show that agriculture production has a positive and significant impact on foreign direct investment. However, public spending in agriculture has a negative and significant influence on the foreign direct investment inflows in agriculture. In addition, Granger causality results show causality flowing from public agriculture spending, net export and inflation  to foreign direct investment inflows in agriculture. Hence, it is recommended that  policymakers should take practical steps towards total eradication of misallocation and squandering of the available funds and redirected toward bridging infrastructural deficits, land restitution to promote foreign direct investment inflows the development of agriculture

APOE Isoforms Control Pathogenic Subretinal Inflammation in Age-Related Macular Degeneration

International audienc

Rôles des chimiokines dans le développement de la dégénérescence maculaire liée à l’âge

International audienceRole of chemokines in the development of age-related macular degeneration. Age-related macular degeneration (AMD) is the main cause of irreversible blindness in industrialized nations. Recent research has emphasized the importance of inflam-matory processes in pathogenesis of this disease. Chemotactic cytokines also named chemokines are important mediators of inflammation and might have a role in development of this disease. They appear to be crucial in the subretinal microglia / macrophage accumulation observed in AMD and may participate in the development of retinal degeneration and in choroidal neovascularization. This paper reviews the possible implication of chemokines in the development of AMD.La dégénérescence maculaire liéeà l'âge (DMLA) est la principale cause de cécité irréversible dans les pays industrialisés. Lesétudes récentes mettent en exergue l'importance des processus inflammatoires dans le développement de la maladie. Les cytokines chimiotactiques, dénommées chimiokines, qui apparaissent comme des médiateurs importants de l'inflammation, pourraient jouer un rôle dans le développement de la DMLA. Plus particulièrement, elles semblent indispensables dans le processus d'accumulation des microglies/macrophages dans l'espace sous-rétinien observé au cours de la DMLA. Elles pourraient par conséquent partici-per au développement de la dégénérescence rétinienne et de la néovascularisation choroïdienne. Dans cette revue, nous décrirons l'implication des chimiokines et de leurs récepteurs dans le développement de la DMLA