Scalloped channels enhance tear mixing under hydrogel contact lenses.

PurposeTear exchange under a soft contact lens is directly related to the amount of lateral and transverse lens motion. Hydrodynamic modeling suggests that channels placed on the back surface of a soft lens will reduce fluid resistance and increase transverse lens movement. This study measured the effect of posterior lens surface scalloped channels on tear exchange.MethodsTear exchange in the postlens tear film (PoLTF) was estimated using a fluorometer to measure the exponential depletion of high-MW fluorescein under the lens expressed as the time to deplete 95% of dye (T95). A total of 32 subjects wore two pairs of identical lenses except that the experimental lens had 12 scalloped channels placed radially in the midperiphery of the posterior lens surface, whereas lenses without channels served as controls.ResultsThe mean +/- standard error T95 values for the channel lenses was 28 +/- 2 minutes compared with 32 +/- 2 minutes for the control lenses (p = 0.107). There was a marginally significant difference in T95 between two lens groups in Asian eyes (p = 0.054).ConclusionPlacing scallop-shaped channels on high-H2O content soft lenses improved the postlens tear pumping in Asian eyes

Scalloped channels enhance tear mixing under hydrogel contact lenses.

PurposeTear exchange under a soft contact lens is directly related to the amount of lateral and transverse lens motion. Hydrodynamic modeling suggests that channels placed on the back surface of a soft lens will reduce fluid resistance and increase transverse lens movement. This study measured the effect of posterior lens surface scalloped channels on tear exchange.MethodsTear exchange in the postlens tear film (PoLTF) was estimated using a fluorometer to measure the exponential depletion of high-MW fluorescein under the lens expressed as the time to deplete 95% of dye (T95). A total of 32 subjects wore two pairs of identical lenses except that the experimental lens had 12 scalloped channels placed radially in the midperiphery of the posterior lens surface, whereas lenses without channels served as controls.ResultsThe mean +/- standard error T95 values for the channel lenses was 28 +/- 2 minutes compared with 32 +/- 2 minutes for the control lenses (p = 0.107). There was a marginally significant difference in T95 between two lens groups in Asian eyes (p = 0.054).ConclusionPlacing scallop-shaped channels on high-H2O content soft lenses improved the postlens tear pumping in Asian eyes

Inclusive Unions in a Dualised Labour Market? The Challenge of Organising Labour Market Policy and Social Protection for Labour Market Outsiders

Dynamics of labour market dualisation have affected most Western European countries over the last two decades and trade unions have been often seen as conservative institutions protecting the interests of their core constituencies and as such contributing to labour market dualisation. However, empirical evidence from Italy shows that unions' stance towards atypical workers has been more inclusive than the literature expected, despite the conditions for pro-insider policies being firmly in place, and unions have emerged as important actors in the organisation of social protection for labour market outsiders. By analysing unions' strategies towards temporary agency workers in Italy through a disaggregated approach (i.e. focussing separately on salary and job protection; active labour market policies; and income protection), I reconcile the empirical observations that conflict with the theoretical expectations. I argue that unions have indeed put in place inclusive, yet selective, policies towards atypical workers and that unions' identity is a central explanatory variable to understand the puzzling coexistence of a dualised labour market and (selectively) inclusive unions. Through a disaggregated identity-bound analysis of unions' strategies, I shed new light on the complex relationship between labour market dualisation and the dualisation of social protection. In particular, findings suggest that paradoxically unions' strategies to counteract labour market dualisation may be furthering the insider-outsider divide in terms of social protection. I also suggest that a clearer analytical distinction between labour market dualisation and welfare dualisation is needed in future research and that the understanding of unions' strategies towards marginal workers would greatly benefit from a systematic disaggregated analysis of unions' agency