Curvature correction to the mobility of fluid membrane inclusions

For the first time, using rigorous low-Reynolds-number hydrodynamic theory on curved surfaces via a Stokeslet-type approach, we provide a general and concise expression for the leading-order curvature correction to the canonical, planar, Saffman-Delbrück value of the diffusion constant for a small inclusion embedded in an arbitrarily (albeit weakly) curved fluid membrane. In order to demonstrate the efficacy and utility of this wholly general result, we apply our theory to the specific case of calculating the diffusion coefficient of a locally curvature inducing membrane inclusion. By including both the effects of inclusion and membrane elasticity, as well as their respective thermal shape fluctuations, excellent agreement is found with recently published experimental data on the surface tension dependent mobility of membrane bound inclusions

Integrating Time in Public Policy: Empirical Description of Gender-Specific Outcomes and Budgeting

Incorporating time in public policymaking is an elusive area of research. Despite the fact that gender budgeting is emerging as a significant tool to analyze the socioeconomic impacts of fiscal policies and thus identify their impacts on gender equity, the integration of time-use statistics in this process remains incomplete, or is even entirely absent, in most countries. If gender budgeting is predominantly based on the index-based empirical description of gender-specific outcomes, a reexamination of the construction of the gender (inequality) index is needed. This is necessary if we are to avoid an incomplete description of the gender-specific outcomes in budget policymaking. Further, "hard-to-price" services are hardly analyzed in public policymaking. This issue is all the more revealing, as the available gender-inequality index - based on health, empowerment, and labor market participation - so far has not integrated time-use statistics in its calculations. From a public finance perspective, the gender budgeting process often rests on the assumption that mainstream expenditures, such as public infrastructure, are nonrival in nature, and that applying a gender lens to these expenditures is not feasible. This argument is refuted by time budget statistics. The time budget data reveal that this argument is often flawed, as there is an intrinsic gender dimension to nonrival expenditures

Microsimulation as a tool for evaluating redistribution policies

During the last twenty years, microsimulation models have been increasingly applied in qualitative and quantitative analysis of public policies. This paper provides a discussion on microsimulation techniques and their theoretical background as a tool for the analysis of public policies with particular attention to redistribution and social policies. Basic principles in using microsimulation models and interpreting their results are analyzed, with particular emphasis on tax incidence, redistribution and poverty analysis. Social welfare analysis permitted by microsimulation techniques is also discussed. Finally, the paper points to limits of present approaches and directions for future research.Au cours des vingt dernières années, l'utilisation des modèles de microsimulation des politiques de redistribution n'a cessé de croître. Cet article offre un rapide survol de ces modèles, l'accent étant mis sur les développements récents dans ce domaine de l'économie appliquée et sur quelques directions de recherche future

The Anatomy of the bill Tip of Kiwi and Associated Somatosensory Regions of the Brain: Comparisons with Shorebirds

Three families of probe-foraging birds, Scolopacidae (sandpipers and snipes), Apterygidae (kiwi), and Threskiornithidae (ibises, including spoonbills) have independently evolved long, narrow bills containing clusters of vibration-sensitive mechanoreceptors (Herbst corpuscles) within pits in the bill-tip. These ‘bill-tip organs’ allow birds to detect buried or submerged prey via substrate-borne vibrations and/or interstitial pressure gradients. Shorebirds, kiwi and ibises are only distantly related, with the phylogenetic divide between kiwi and the other two taxa being particularly deep. We compared the bill-tip structure and associated somatosensory regions in the brains of kiwi and shorebirds to understand the degree of convergence of these systems between the two taxa. For comparison, we also included data from other taxa including waterfowl (Anatidae) and parrots (Psittaculidae and Cacatuidae), non-apterygid ratites, and other probe-foraging and non probe-foraging birds including non-scolopacid shorebirds (Charadriidae, Haematopodidae, Recurvirostridae and Sternidae). We show that the bill-tip organ structure was broadly similar between the Apterygidae and Scolopacidae, however some inter-specific variation was found in the number, shape and orientation of sensory pits between the two groups. Kiwi, scolopacid shorebirds, waterfowl and parrots all shared hypertrophy or near-hypertrophy of the principal sensory trigeminal nucleus. Hypertrophy of the nucleus basorostralis, however, occurred only in waterfowl, kiwi, three of the scolopacid species examined and a species of oystercatcher (Charadriiformes: Haematopodidae). Hypertrophy of the principal sensory trigeminal nucleus in kiwi, Scolopacidae, and other tactile specialists appears to have co-evolved alongside bill-tip specializations, whereas hypertrophy of nucleus basorostralis may be influenced to a greater extent by other sensory inputs. We suggest that similarities between kiwi and scolopacid bill-tip organs and associated somatosensory brain regions are likely a result of similar ecological selective pressures, with inter-specific variations reflecting finer-scale niche differentiation