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The world's river deltas may collapse under the combined effects of rising sea levels, subsidence, and reduced sediment supply. Saving these deltaic environments requires quantifying processes driving collapse. In the Mississippi River Delta, rapid land loss offers an important opportunity to test existing theories for marsh collapse. We use Landsat images to examine how pond expansion by edge retreat contributes to land loss over 34 years in the Atchafalaya‐Vermillion, Terrebonne, and Barataria basins of the Mississippi Delta. Tracking the area changes in ponds on the marsh surface, we find a striking consistency between pond expansion direction and the dominant wind direction and show that wind‐generated waves are capable of causing edge erosion. Expansion rate increases rapidly for ponds wider than 300 m in Terrebonne and Barataria basins. From this, we suggest that ponds in Atchafalaya‐Vermillion basin are stable, whereas ponds in Terrebonne and Barataria are unstable. Wind‐driven pond expansion on Mississippi River Delta Plain is leading to land loss

Using energetics-based formulations for wave-driven sediment transport, we develop a robust methodology for estimating the morphodynamic evolution of a cross-shore sandy coastal profile. In our approach, wave-driven cross-shore sediment flux depends on three components: two onshore-directed terms (wave asymmetry and wave streaming) and an offshore-directed slope term. In contrast with previous work, which applies shallow water wave assumptions across the transitional zone of the lower shoreface, we use linear Airy wave theory. The cross-shore sediment transport formulation defines a dynamic equilibrium profile and, by perturbing about this steady state profile, we present an advection-diffusion formula for profile evolution. Morphodynamic Péclet analysis suggests that the shoreface is diffusionally dominated. Using this depth-dependent characteristic diffusivity timescale, we distinguish a morphodynamic depth of closure for a given time envelope. Even though wave-driven sediment transport can (and will) occur at depths deeper than this morphodynamic closure depth, the rate of morphologic bed changes in response to shoreline change becomes asymptotically slow. Linear wave theory suggests a shallower shoreface depth of closure and much sharper break in processes than shallow water wave assumptions. Analyzing hindcasted wave data using a weighted frequency-magnitude approach, we determine representative wave conditions for selected sites along the U.S. coastline. Computed equilibrium profiles and depths of closure demonstrate reasonable similarities, except where inheritance is strong. The methodology espoused in this paper can be used to better understand the morphodynamics at the lower shoreface transition with relative ease across a variety of sites and with varied sediment transport equations. Presents energetics-based formulation for the evolution of sandy wave-dominated profilesDerives estimation of a temporally defined morphodynamic depth of closureImportant to use linear Airy wave theory versus shallow water wave assumptions

ABSTRACTCourses in Portuguese for Speakers of Other Languages, in particular for adult immigrants, have been steadily expanding in Portugal over the last 15 years. These programmes aim to promote educational and labour market integration, access to Portuguese nationality, and cognitive development. This paper argues that official Portuguese learning policies have mainly targeted a population with an immigrant background that fails to represent the full range of adult immigrants’ needs. In particular, less educated adult immigrants’ educational needs have been persistently neglected. Considering that, hitherto, approximately 9% of trainees have been adult immigrants with little or no schooling, this group has not received sufficient attention in policy measures, nor has it been fully accommodated in institutional terms. As a starting point, the paper identifies the place of adult immigrant literacy in international and national discussions. Subsequently, it discusses the main official programmes offering Portuguese for Speakers of Other Languages to adult immigrants. The data from the main programmes were backed up by fieldwork, in particular interviews carried out with teachers and public officials which highlight the main barriers and strategies impacting on this group. Finally, we argue that programmes should consider tailor-made solutions, given the counterproductive heterogeneity of classes and the arbitrariness of informal procedures.

Adopting a psycho-sociopolitical approach, the present paper describes the results of a community-based participatory needs assessment focusing on the perceived needs of women of reproductive age as users of primary healthcare in contexts of migration-driven diversity and socioeconomic vulnerability in the Metropolitan Area of Lisbon. The investigation comprised 64 in-depth interviews with women, including natives and immigrants to Portugal from the main origin countries in the context under study (Brazil, Cape Verde, and other Portuguese-speaking African countries) and a survey of 125 women, again natives and immigrants from these countries. The central role of qualitative methodology and grounded theory, in the framework of a multi-method research, allowed understanding the needs of women as embedded in contexts characterized by asymmetrical power relations, in terms of unequal opportunities and resources, at multiple interrelated ecological levels (personal, relational, organizational, community, socioeconomic, health system/policy, cultural/migration). The priority perceived needs of women were primarily related to socioeconomic disadvantage, severely aggravated in the current contexts of crisis; and factors at the health system level, mainly unequal access to family doctors, excessive waiting lists, and increases in the direct costs of healthcare. Results allow questioning the adequacy of cultural competence approaches for the reduction of inequalities in maternal-child healthcare in the context under study, showing the critical and innovative value of qualitative methodology and grounded theory in research on social justice and health in contexts of diversity characterized by unequal power dynamics.

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This experimental study describes the mean and turbulent flow structure in the wake of a circular array of cylinders, which is a model for a patch of emergent vegetation. The patch diameter, D, and patch density, a(frontal area per volume), are varied. The flow structure is linked to a nondimensional flow blockage parameter, CDaD, which is the ratio of the patch diameter and a drag length scale (CDa)−1. CDis the cylinder drag coefficient. The velocity exiting the patch, Ue, is reduced relative to the upstream velocity, U∞, and Ue/U∞decreases as flow blockage (CDaD) increases. A predictive model is developed for Ue/U∞. The wake behind the patch contains two peaks in turbulence intensity. The first peak occurs directly behind the patch and is related to turbulence production within the patch at the scale of individual cylinders. The second peak in turbulence intensity occurs at distance Lwdownstream from the patch and is related to the wake‐scale vortices of the von Karman vortex street. The presence of the flowUein the wake delays the formation of the von Karman vortex street until distance L1(

An efficient access towards isoindolinones (V) is presented, involving the synthesis of thermally stable carbamoylxanthates (IV) from N‐tert‐butyl‐N‐benzylamines (I), the generation of the corresponding carbamoyl radicals and their cyclization—rearomatization reaction.