Contact lens platforms for ocular health monitoring

As of today, the World Health Organization (WHO) counts millions of cases of preventable blindness every year in high income countries, attributed to the lack of early-stage ophthalmic screening technologies. Contemporary methods rely on bulky and costly equipment exclusively operated by specialized clinicians, resulting in a medical approach based on reaction over prevention. A possible approach results from a literature survey on the tear fluid properties, which revealed its potential to be used as a diagnostic medium. However, existing tear sampling technologies lack practicality, and introduce a high contamination risk of tear samples

Greil Marcus, Three Songs, Three Singers, Three Nations

Cette traduction de l’ouvrage de Greil Marcus, paru dans sa version originale en 2015 aux Harvard University Press, est une adaptation de ses conférences de 2013 à l’université d’Harvard. Dépourvu d’introduction et de conclusion, il est composé de trois chapitres traitant chacun d’un morceau que Marcus qualifie de « folk song », ce que le traducteur a choisi de rendre par « chansons traditionnelles » : « Ballad of Hollis Brown » de Bob Dylan, « Last Kind Words Blues » de Geeshie Wiley et « I ..

Proceedings of the OECD/PACIOLI Workshop on Information Needs for the Analysis of Farm Household Income Issues

The assessment of agricultural policies depends more and more on micro-economic data sets. This is especially true for policies with an income objective in a situation where farm households have different income sources. Among others the OECD has stressed this point in recent years with analytical reports. The PACIOLI network yearly brings together data managers and researchers interested in the innovation of data collection in this area. In April 2004 a joint workshop was organised at the OECD in Paris to bring experts together to exchange best practices. This report contains the proceedings of that workshop

Introduction : Les mutations de la famille agricole

La place de la femme en agriculture a suivi les évolutions sociales. La famille agricole a connu en ce sens des mutations équivalentes à celles de la société dans son ensemble, même si comme le rappelle Hubert Bosse-Platière, il est notoirement connu que l’on divorce moins chez les agriculteurs, et que l’on a moins qu’ailleurs des enfants hors mariage. La particularité de la famille agricole se trouve selon Alice Barthez dans la réunion au sein d’une même structure de la famille et de la prof..

Laser-inscribed contact lens sensors for the detection of analytes in the tear fluid

Tears exhibit compositional variations as a response to ocular and systemic metabolic conditions, and they can therefore be used for the assessment of physiological health. Here, microfluidic contact lenses were developed as wearable platforms for in situ tear pH, glucose, protein, and nitrite ions sensing. The microfluidic system was inscribed in commercial contact lenses by CO2 laser ablation. The microchannel consisted on a central ring with four branches, and biosensors were embedded within microcavities located at the branches ends. The device was tested with artificial tears and colorimetric readouts were performed using a smartphone-MATLAB algorithm based on the nearest neighbor model. Sensors responded within a time range of 15 s, and yielded sensitivities of 12.23 nm/pH unit, 1.4 nm/mmol L−1 of glucose, 0.49 nm/g L−1 of proteins, and 0.03 nm/μmol L−1 of nitrites. Contact lens sensing platforms may provide on-eye tears screening with applications in the monitoring of the ocular health both in clinics and at point-of-care settings

Decreasing pH impairs sexual reproduction in a Mediterranean coral transplanted at a CO2 vent

Ocean acidification, due to the increase of carbon dioxide (CO2) concentration in the atmosphere and its absorption by the oceans, affects many aspects of marine calcifying organisms' biology, including reproduction. Most of the available studies on low pH effects on coral reproduction have been conducted on tropical species under controlled conditions, while little information is reported for either tropical or temperate species in the field. This study describes the influence of decreasing pH on sexual reproduction of the temperate non-zooxanthellate colonial scleractinian Astroides calycularis, transplanted in four sites along a natural pH gradient at the underwater volcanic crater of Panarea Island (Tyrrhenian Sea, Italy). The average pH values of each site (range: pHTS 8.07–7.40) match different scenarios of the Intergovernmental Panel on Climate Change (IPCC) for the end of the century. After 3 months under experimental conditions, the reproductive parameters of both oocytes and spermaries (abundance, gonadal index, and diameters) seem to be unaffected by low pH. However, a delay in spermary development in the pre-fertilization period and a persistence of mature oocytes in the fertilization period were observed in the most acidic site. Furthermore, no embryos were found in colonies from the two most acidic sites, suggesting a delay or an interruption of the fertilization process due to acidified conditions. These findings suggest a negative effect of low pH on A. calycularis sexual reproduction. However, long-term experiments, including the synergistic impact of pH and temperature, are needed to predict if this species will be able to adapt to climate change over the next century

Anthocyanin-functionalized contact lens sensors for ocular pH monitoring

Anthocyanins are bioactive compounds naturally found in a variety of leaves, fruits, and vegetables. Anthocyanin pigments undergo a modification in their chemical structure when exposed to different concentrations of hydrogen ions, and they were extensively studied to be used as active elements in biocompatible pH sensors. The ocular pH is a significant parameter to assess the ocular physiology in cases of postocular surgery, keratoconjunctivitis, and ocular rosacea. Contact lenses have the potential to be used as medical diagnostic devices for in situ continuous monitoring of the ocular physiology. Here, anthocyanin-functionalized contact lenses were developed as wearable sensors to monitor the ocular pH. Anthocyanin pigments were extracted from Brassica oleracea and used to functionalize the polymeric matrices of commercial soft contact lenses by soaking and drop-casting processes. Contact lenses responded to the physiological ocular pH of 6.5, 7.0, and 7.5, exhibiting a systematic color shift from pink (pH 6.5) to purple (pH 7.0) and blue (pH 7.5). The functionalization of contact lens sensors was evaluated as a function of the dye concentration. Quantitative values were obtained by comparing the RGB triplets of the colors obtained with the naturally extracted dye and with delphinidin chloride dye in 0.0 to 1.5 mmol L–1 aqueous solution. The functionalization of contact lenses was studied as a function of the soaking time, resulting in best results when soaking for 24 h. The dye leakage from the contact lenses in deionized water was evaluated, and a negligible leakage after 18 h was observed. Poly-2-hydroxy ethylmethacrylate contact lenses were fabricated and cross-linked with anthocyanin dye, resulting in a slight color shift upon pH changes from 6.5 to 7.4. Contact lens pH sensors may be used to continuously monitor the ocular pH at point-of-care settings

Contact lens-based microchannel rings for detecting ocular hypertension

Glaucoma is a major cause of irreversible blindness worldwide. The most acknowledged biomarker to diagnose and monitor glaucoma progression is intraocular pressure (IOP). Gold standard techniques for IOP monitoring are invasive, uncomfortable, and require visiting a clinic. In addition, most methods only provide a single snapshot on widely varying parameters. On the other hand, contact lenses have attracted particular interest to be used as continuous monitoring platforms to incorporate sensors, drugs, and more. Here, commercial contact lenses were laser-processed to be capable of detecting IOP variations in the physiological range. Three ring-couples with interspaces of 1.0, 1.5, and 2.0 mm were engraved on three soft contact lenses separately by using a carbon dioxide laser. The IOP/pressure variations induced repeatable changes in the ring-couple interspace which acted as a smartphone-readable pressure sensor. The processed contact lenses may be a potential candidate toward IOP monitoring at point-of-care settings

Integration of paper microfluidic sensors into contact lenses for tear fluid analysis

In this article, using the integration of paper microfluidics within laser-inscribed commercial contact lenses, we demonstrate the multiplexed detection of clinically relevant analytes including hydrogen ions, proteins, glucose, nitrites and l-ascorbic acid, all sampled directly from model tears. In vitro measurements involved the optimization of colorimetric assays, with readouts collected, stored and analyzed using a bespoke Tears Diagnostics smartphone application prototype. We demonstrate the potential of the device to perform discrete measurements either for medical diagnosis or disease screening in the clinic or at the point-of-care (PoC), with future applications including monitoring of ocular infections, uveitis, diabetes, keratopathies and assessing oxidative stress

The inventors of American Folk Music from the progressive era to the New Deal : around the collector Sidney Robertson

À partir des années 1890, la construction de l’identité nationale américaine et d’un citoyen moderne mobilise différentes définitions de la notion de folk music, issues de différents milieux intellectuels et fondées sur une multiplication des collectes, pour culminer à la fin du New Deal en l’établissement d’un consensus sur l’existence et le contenu de base de l'American Folk Music. Compositeurs et musicologues construisent l’American Folk Music pour tenter de fonder une école de composition américaine qui rivaliserait avec les écoles européennes. Les folkloristes universitaires l’abordent en tant qu’objet d’étude, selon une approche textualiste et donc nécessairement anglo-centrée. Des anthropologues se saisissent aussi de cette notion pour l'appliquer aux musiques amérindiennes, puis à celles des Noirs-Américains. Avec les psychologues, ils y introduisent les influences des approches évolutionniste, diffusionniste, fonctionnaliste et relativiste. Éducateurs progressistes et travailleurs sociaux l’emploieront dans des projets d’ingénierie sociale, notamment en relation avec le mouvement d'américanisation. Tous ces paradigmes coexistent et s’opposent ou s’influencent jusque dans les années 1930, moment où l’institutionnalisation de l’American Folk Music au sein de l’État fédéral conduit à une rencontre et une forme de synthèse de toutes ces approches. Cette thèse explore les travaux des inventeurs de l’American Folk Music autour du parcours d’une des collectrices qui établissent la synthèse new-dealienne, Sidney Robertson.From the 1890's on, the construction of American national identity and of the modern citizen draws on various definitions of the notion of folk music, produced by various intellectual circles and supported by the development of field collecting, to result towards the end of the New Deal Era in a tentative consensus on the basic content and the very existence of American Folk Music. Composers and musicologists address American Folk Music as a tool to try and set up an American composition school to rival the european ones. Academic folklorists approach it as a scholarly object through a text-centered paradigm requiring its linguistic anglo-centeredness. Anthropologists apply the notion to Amerindian, then later on Black-American musics. Along with the psychologists, they introduce in its definition the new concepts and bias of the competing evolutionist, diffusionist, functionalist and relativist theoretical schools. Progressive educators and social workers use it in their social engineering programs, most importantly in the Americanization-related ones.These various paradigms coexist, compete, and influence each other until the 1930's, when the institutionalization of American Folk Music inside Federal State agencies encourages a synthesis of these different approaches. The present thesis aims to describe the works and ideas of these various contributors to the invention of the American Folk Music through the study of the life and career of one of the New Deal collectors instrumental in this synthesis, Sidney Robertson